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COMMONWEALTH, Volume 20, Issue 1 (2018). © 2018 The Pennsylvania Political Science Association.  
ISSN 2469-7672 (online). http://dx.doi.org/10.15367/com.v20i1.180. All rights reserved.

Party Identification, Voter Attitudes,  
and Voter Behavior in New Jersey and 
Pennsylvania, 1980–2012

Real Difference or Election Law Mirage?

JAMES E. VIKE
Widener University

This study examines the extent to which pronounced differences in voter reg-
istration statistics between Pennsylvania and New Jersey are truly indicative 
of significant differences in political attitudes and voter behavior across citi-
zens of these neighboring states. The analysis is based upon an examination of 
cumulative 1980–2012 American National Election Study (ANES) survey data. 
Although there is evidence that minor differences in partisan attachments exist, 
there is no evidence that these differences are manifest in diminished interest, 
efficacy, polarization levels, participation rates, or straight-ticket voting behav-
ior. The central conclusion of this study is that the elevated tendency of New 
Jersey voters to register as unaffiliated is less of a marker of greater independent 
orientations and more of an election law mirage that furthers a myth of mount-
ing citizen independence from partisan affiliations. Furthermore, these find-
ings support the conclusion that a follow-up methodology for determining true 
partisan attachments among ANES respondents is a more accurate predictor of 
partisan attitudes and behavior than methods relying upon an initial probe of 
self-identified partisanship or statewide voter registration statistics.

A quick look at 2016 voter registration statistics in New Jersey and 
Pennsylvania highlights a dramatic difference in overt declarations 
of party affiliation among citizens of these neighboring states. Voter 



62 JaMes e. Vike

registration data in the Commonwealth of Pennsylvania, a state with a closed 
primary system that restricts participation in primary elections to only those 
registered for a particular party, show that over 85% of registered voters affili-
ate with one of the two major parties. New Jersey, on the other hand, features 
a modified closed primary system, where affiliated voters may only vote in 
their party primary but unaffiliated voters are free to choose in which primary 
they wish to participate.1 This difference in election participation policies has 
allowed 43% of New Jersey voters to register as unaffiliated without relin-
quishing their option to participate in primary elections.

Figure 1 displays a detailed distribution of 2016 voter registration data 
between the two states. While both states have greater numbers of registered 
Democrats than registered Republicans, the difference in registration rates for 
unaffiliated voters is dramatic and worthy of further study. Subsequent analy-
sis of this disparity is necessary and important because a substantial volume 
of research has found meaningful linkages between party attachments and 
voter attitudes and behavior.

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Pennsylvania  Registered  Voters  2016 New  Jersey  Registered  Voters  2016

Republicans Independents/UNA/NE Democrats

figure 1. Comparing Voter Registration Statistics: Pennsylvania and New Jersey.* (Source: Voter 
registration data for the Commonwealth of Pennsylvania were derived from the PA Department 
of State, Voter Registration Division’s report of official voter registration statistics from November 
8, 2016. Voter registration data for New Jersey were derived from the NJ Department of State, 
Division of Elections’ monthly voter registration summary report from November 7, 2016.)

* To ease comparison with ANES party identification data, percentages of individuals registered 
with other parties are not displayed in this chart. Just over 5% of PA voters and less than 1% of 
NJ voters were registered under a third-party banner in 2016.



Party Identification, Voter Attitudes, and Voter Behavior in  NJ and PA 63

This study examines the extent to which these pronounced differences 
in voter registration actually indicate real and significant differences in voter 
attitudes and behavior. More specifically, this study examines cumulative 
1980–2012 American National Election Study (ANES) survey data from New 
Jersey and Pennsylvania to address the following question: Is this disparity 
in unaffiliated party registration a marker of vastly different attitudes and 
behaviors among citizens of these states or merely a mirage produced by more 
liberal registration requirements that further a myth of citizen independence 
from partisan affiliations?

The choice of factors for comparison is informed by numerous studies that 
have outlined a range of tangible differences across attitudinal and behavioral 
dimensions linked to the strength of partisan attachments (Campbell et al. 1960; 
Keith et al. 1992; Lewis-Beck et al. 2008; Magleby, Nelson, and Westlye 2011; 
Dalton 2013). If the differences in actual voter registration levels between the 
two states are truly indicative of differing partisan attachments, then we can 
expect the comparative analysis of ANES data to highlight differences along 
these dimensions—with the more party-oriented citizens of the Commonwealth 
of Pennsylvania exhibiting higher rates of interest, efficacy, activism, and polar-
ization than the supposedly more “independent-oriented” citizens of New Jersey.

Methodological Differences in Tracking  
Partisan Identification

There are two basic approaches to tracking party identification across the 
American electorate. One approach examines state-level voter registration 
statistics, while the other examines self-identification rates obtained through 
responses to survey questions. A solid majority of party identification scholars 
have tended to prefer the latter approach. The stated rationale for adopting 
this approach includes: (1) self-identification is deemed to be a more fitting 
and time-sensitive approach for measuring partisanship when defined as an 
individual’s psychological attachment to a particular party; (2) actual voter 
registration statistics are thought to potentially mask true attachments due 
to vastly different laws, traditions, and customs across the states; and (3) sur-
vey responses provide rich datasets enabling in-depth comparative analysis of 
voter affinities, attitudes, and behaviors.

Despite overwhelming reliance upon the self-identification approach in 
the scholarly community, there still remains some disagreement over the 
ideal method of tabulating voter attachments among survey respondents. 
At the core of the dispute is the sequence of two partisan self-identification 
questions posed in ANES surveys, as originally outlined in The American 
Voter (Campbell et al. 1960). The initial question probing personal partisan 



64 JaMes e. Vike

attachments sorts respondents into three pools: Democrats, Republicans, and 
Independents. A follow-up question probes either the strength of the partisan 
attachment or whether an independent leaned toward a particular party. The 
two question sequence has the effect of creating a seven-point scale of partisan 
identification. In-depth analysis of the resulting data led Campbell and his 
colleagues to determine that partisan attachment was a crucial predictor of 
voter attitudes, preferences, and behavior.

Disagreements over this methodology emerged several decades later when 
scholars claimed that increasing numbers of self-identifying independents in 
the 1970s signaled a significant decline in partisanship in America and across 
other western democracies (Wattenberg 1984; Miller 1991; Dalton and Wat-
tenberg 2000). These “party decline” scholars argued that a rise in the number 
of individuals identifying as independents in response to the initial survey 
query indicated a declining attachment to political parties within the elector-
ate and subsequently signaled a diminished reliance upon partisanship as a 
cue for political attitudes and behavior. Dalton (2013) more recently argues 
that an individual’s initial expression of disaffection from party attachments 
is a meaningful indicator of an enduring independent-oriented political iden-
tity and signals a greater propensity to eschew party-line voting over time. 
McGhee and Krimm (2009) and Dalton (2013) also rank among the small 
cohort of scholars who champion analysis of actual voter registration statis-
tics as a preferred method of gauging partisan identification patterns among 
American voters. Both point to modest increases in unaffiliated registrations 
in recent years as a sign that voters are becoming less sympathetic toward the 
major parties. McGhee and Krimm additionally assert that the new indepen-
dent voters are less polarized along partisan and ideological lines.

The early claims of declining partisanship were summarily contested by a 
team of scholars charging that the apparent rise of independents was actually 
a product of misguided methodological choices (Keith et al. 1992). The “myth 
of the independent voter” argument contends that partisan attachments have 
not really declined, because follow-up partisanship questions in ANES sur-
veys show that many self-identified independents clearly lean toward one 
particular party. They purport that true independents are less interested, less 
informed, express lower levels of polarization, and participate at substantially 
lower levels, but dispute that the rolls of independents are on the rise. Several 
updated studies have reinforced this finding for more recent election cycles, 
showing that contemporary independent leaners exhibit attitudes and behav-
iors more in line with partisans than true independents (Kaufmann, Petro-
cik, and Shaw 2008; Petrocik 2009; Magleby, Nelson, and Westlye 2011). A 
thorough reexamination of the original American voter study reaffirmed the 
contention that strength of partisan identification impacts party-line voting, 



Party Identification, Voter Attitudes, and Voter Behavior in  NJ and PA 65

candidate assessments, party assessments, interest in campaigns, and concern 
for election outcomes (Lewis-Beck et al. 2008).

A common practice arising from this methodological dispute is to rou-
tinely track two different three-point scale measures of partisan identifica-
tion: one relying upon the initial expression of partisan identification that 
places independent-leaners in the category of independent voters; and the 
other relying upon the follow-up responses that places independent-leaners 
with their party of preference.

Party Identification Variations in Pennsylvania  
and New Jersey

Of particular relevance for this study is the extent to which current Pennsylva-
nia and New Jersey voter registration statistics highlight the dispute over the 
ideal manner for tabulating voter attachments in the United States. Examina-
tion of official voter registration statistics shows that these two states closely 
track with nationwide trends across the dual partisan identification method-
ologies. Figure 2 shows that actual voter registration rates in Pennsylvania 

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Republicans Independents/UNA/NE Democrats

ANES  Party  ID  With  Leaners  2012

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Pennsylvania  Registered  Voters  2016

figure 2. Comparing Partisan Identification: ANES 3-Point Scale with Leaners and Official 
Pennsylvania Registration Statistics. (Source: ANES party identification data were derived from 
the ANES 2012 Time Series Study [available at www.electionstudy.org]. Voter registration data 
for the Commonwealth of Pennsylvania were derived from the PA Department of State, Voter 
Registration Division’s report of official voter registration statistics from November 8, 2016.)



66 JaMes e. Vike

closely reflect nationwide partisan distribution rates from the 2012 ANES 
data when independent leaners are included as partisans. Figure 3, on the 
other hand, shows that contemporary New Jersey voter registration data are 
similar to the 2012 ANES data when all self-identified independents are clas-
sified as independents.

Recognizing the clear distinction in partisan registration patterns across 
these two states and their similarities to the dual approaches to interpreting 
self-identified party affiliation offers an intriguing opportunity to re-examine 
the veracity of the “myth of the independent voter” thesis at the state level.

Comparative Findings

The following tables display findings across a range of party attachment, atti-
tude, and behavioral factors examined in the statistical comparison between 
Pennsylvania and New Jersey citizens. Partisan measures include the dis-
tribution of partisan identification in response to the initial partisanship 
probe, the partisanship distribution after independent leaners are merged 

figure 3. Comparing Partisan Identification: ANES 3-Point Scale without Leaners and Official 
New Jersey Registration Statistics. (Source: ANES party identification data were derived from 
the ANES 2012 Time Series Study [available at www.electionstudy.org]. Voter registration data for 
New Jersey were derived from the NJ Department of State, Division of Elections’ monthly voter 
registration summary report from November 7, 2016.)

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ANES  Party  ID  Without  Leaners  2012 New  Jersey  Registered  Voters  2016



Party Identification, Voter Attitudes, and Voter Behavior in  NJ and PA 67

with partisans, and the strength of partisan attachments. The examination of 
potential differences across attitudinal measures includes interest in elections, 
feelings of efficacy toward electoral outcomes, and levels of affective polarized 
thinking toward the major parties and presidential candidates. Behavioral 
comparisons include attainment of political information, voter turnout rates, 
overall political activism levels, and party-line voting.

Table 1 collectively displays the empirical results across the range of com-
parisons. The initial intriguing finding is the apparent disconnect among the 
differences across the three dimensions. Each of the three partisan attachment 
measures indicated statistically significant differences between the states, 
while only one of eight attitudinal and behavior measures indicated a statisti-
cal difference. At first glance, the significant differences in partisan attach-
ments offers support for the view that New Jersey’s more independent-friendly 
voter registration data is actually a marker of a less partisan state. Levels of 
self-identified affinity to a particular political party are lower in New Jer-
sey when measured by the initial question and also once independent leaners 
are merged with party identifiers. Although statistically significant, the chi-
square values are actually quite low and will be examined more closely below.

table 1. Differences in Party attachments, Political attitudes, and Voter  
Behavior—Pennsylvania and new Jersey, 1980–2012

Difference 
Value

Degrees of 
freedom

statistical 
significance

Partisan Measures

Party Identification (Initial) χ2 = 24.754 2 0.000***

Party Identification (Leaners as Partisans) χ2 =  9.589 2 0.008**

Strength of Party Attachments χ2 = 30.717 3 0.000***

attitudinal Measures

Interest in Elections χ2 = 2.061 2 0.357

Concern over Election Outcomes χ2 = 0.144 1 0.704

Presidential Candidate Affect Polarization χ2 = 8.000 4 0.092

Political Party Assessment Polarization F = 5.168 1 0.023*

Behavioral Measures

Political Information Acquisition χ2 = 4.917 4 0.296

Voter Turnout χ2 = 3.309 1 0.069

Political Activism Levels χ2 = 0.613 3 0.894

Party-line Voting χ2 = 3.030 1 0.082

Source: American National Election Study, Cumulative Data File 1980–2012.

*p < 0.05; **p < 0.01; ***p < 0.001



68 JaMes e. Vike

The absence of statistical significance across three of the four attitudinal 
measures and all four behavioral measures is a startling finding given the 
findings relating to party identification. The nearly uniform absence of differ-
ence across attitudinal and behavioral measures is inconsistent with scholarly 
expectations if New Jersey were actually to be considered a less partisan state 
than Pennsylvania. Distribution patterns relating to concern over the out-
comes of the election and political activism levels are nearly identical between 
the states. While some minor differences are visible across state distributions 
of interest levels, candidate assessment polarization, voter turnout, and will-
ingness to cast a split-ticket ballot, these differences do not meet the signifi-
cance standard. These findings support a conclusion that there are virtually 
no differences between Pennsylvania and New Jersey citizens pertaining to 
political attitudes or electoral behavior.

A more detailed look at the limited range of statistically significant find-
ings is warranted to explore the nature and intensity of partisan and party 
polarization differences between Pennsylvania and New Jersey. Table 2 high-
lights the partisan distributions of state respondents to the ANES surveys over 
time. The table indicates comparative differences between the states, but also 
highlights the volatile impact that methodological choice has on efforts to 
track partisan identification. The percentage value in each cell represents the 
difference in the partisan identification rates between the initial breakdown 
based upon responses to the first partisanship question (Initial) and the sub-
sequent interpretation that counts partisan identification after independent 
leaners have been grouped with their party of preference (Follow-up). This 
table shows that the methodological distinction is particularly impactful on 
New Jersey, since the initial plurality of independent self-identifiers is attrib-
utable to the fact that over one-quarter of respondents can be classified as 
independent leaners.

Table 3 offers a more detailed breakdown of the statistically significant 
differences in the strength of self-classified partisan attachments between 

table 2. Methodological impact on Party identification rates, 1980–2012

new Jersey Pennsylvania

Party iD 
(initial)

Party iD 
(follow-up) change

Party iD 
(initial)

Party iD 
(follow-up) change

Democrats 29.1% 40.4% +11.3% 39.5% 48.5%  +9.0%

Independents 43.5% 16.7% –26.8% 29.6% 11.8% –17.8%

Republicans 27.5% 42.9% +15.4% 30.9% 39.7%  +8.8%

Source: American National Election Study, Cumulative Data File 1980–2012.



Party Identification, Voter Attitudes, and Voter Behavior in  NJ and PA 69

table 3. Distribution of strength of Party identification, 1980–2012

nJ Pa total

Independents / Apoliticals  87
 16.7%

 75
 11.8%

 159
 14.0%

Independent Leaners 136
 27.0%

116
 18.3%

 252
 22.2%

Weak Partisans 161
 32.0%

202
 31.9%

 363
 32.0%

Strong Partisans 122
 24.3%

240
 37.9%

 362
 31.9%

Total 503
100.0%

633
100.0%

1136
100.0%

χ2 = 30.717, df = 3, Sig = 0.000*, Cramer’s V = 0.167

Source: American National Election Study, Cumulative Data File 1980–2012.

*p < 0.001

New Jersey and Pennsylvania citizens. This finding appears to reinforce dis-
parate partisan inclinations represented through voter registration data. New 
Jersey appears more authentically inclined toward independents, featuring 
a higher rate of pure independents (5% more) and independent leaners (9% 
more) than does Pennsylvania. In turn, only one-quarter of New Jersey citi-
zens self-identify as strong partisans, compared to 38% of Pennsylvanians. 
Although the resulting chi-square value denotes a statistically significant dif-
ference in party affinity between the two states, the strength of the association 
is quite weak. The low (0.167) Cramer’s V value indicates that party identi-
fication differences are certainly less dramatic than the initial scan of party 
registration statistics might project.

Table 4 displays a more detailed comparison of the only attitudinal mea-
sure showing a statistically significant difference between New Jersey and 

table 4. Party assessment Polarization comparison 1980–2012

Mean Party standard 
Polarization rating Deviation f Value significance eta Value

New Jersey 28.95  25.65
(N = 496)

5.168 0.023* 0.068
Pennsylvania 32.69  28.60

(N = 626)

Source: American National Election Study, Cumulative Data File 1980–2012.

*p < 0.05



70 JaMes e. Vike

Pennsylvania citizens. The mean polarization value derived from the feel-
ing thermometer ratings of the two major political parties shows that New 
Jersey citizens are slightly less polarized in their assessments of the parties 
than Pennsylvanians. The significance and eta values, however, indicate that 
this difference is substantially limited. When considered in tandem with the 
absence of significant difference in affect assessments of presidential candi-
dates, it can safely be concluded that the pronounced differences in the overt 
registration patterns of citizens of the two states are not indicative of substan-
tial differences in polarization levels.

Conclusions

Although statistical analysis does demonstrate that partisan affiliation dif-
ferences in voter registration statistics between the states are representative of 
small variances in party attachment, the anticipated associations with dimin-
ished partisanship do not hold firm across attitudinal and behavioral mea-
sures. In particular, evidence of lesser partisan attachments in New Jersey is 
not manifest through diminished interest, efficacy, polarization, participation 
rates, or straight-ticket voting behavior.

The fact that disparities in partisan registrations between these two states 
do not foreshadow meaningful differences in political attitudes or voter 
behavior offers clear support for one perspective on the central question of 
this study. The elevated tendency of New Jersey voters to register as unaffili-
ated is less of a marker of greater independent orientations and more of an 
election law mirage that furthers a myth of mounting citizen independence 
from partisan affiliations. Furthermore, these findings support the conclu-
sion that the follow-up methodology for determining true partisan attach-
ments among ANES respondents is a more accurate predictor of partisan 
attitudes and behavior than either the probe of self-identified partisanship or 
statewide voter registration statistics.

NOTE

1. The National Conference of State Legislatures provides an excellent accounting of 
variations in state primary election laws and policies. See http://www.ncsl.org/research/
elections-and-campaigns/primary-types.aspx for additional information about the cat-
egorization of state election systems.

REFERENCES

Campbell, Angus, Philip E. Converse, Warren E. Miller, and Donald E. Stokes. 1960. The 
American Voter. New York: Wiley and Sons.



Party Identification, Voter Attitudes, and Voter Behavior in  NJ and PA 71

Dalton, Russell J., and Martin Wattenberg, eds. 2000. Parties Without Partisans: Political 
Change in Advanced Industrial Democracies. Oxford: Oxford University Press.

Dalton, Russell J. 2013. The Apartisan American: Dealignment and Changing Electoral 
Politics. Thousand Oaks, CA: CQ Press.

Kaufmann, Karen M., John R. Petrocik, and Daron R. Shaw. 2008. Unconventional Wis-
dom: Facts and Myths About American Voters. New York: Oxford University Press.

Keith, Bruce, David Magleby, Candice Nelson, Elizabeth Orr, Mark Westlye, and Ray-
mond Wolfinger. 1992. The Myth of the Independent Voter. Berkeley: University of 
California Press.

Lewis-Beck, Michael, William Jacoby, Helmut Norpoth, and Herbert Weisberg. 2008. The 
American Voter Revisited. Ann Arbor: University of Michigan Press.

Magleby, David, Candice Nelson, and Mark Westlye. 2011. “The Myth of the Independent 
Voter Revisited.” In Facing the Challenge of Democracy: Exploration in the Analysis of 
Public Opinion and Political Participation, eds. Paul Sniderman and Benjamin High-
ton. Princeton, NJ: Princeton University Press, 238–263.

McGhee, Eric, and Daniel Krimm. 2009. “Party Registration and the Geography of Party 
Polarization.” Polity 41 (July): 345–367.

Miller, Warren E. 1991. “Party Identification, Realignment, and Party Voting: Back to 
Basics.” American Political Science Review 85 (June): 557–568.

Petrocik, John. 2009. “Partisan Identification: Leaners Are Not Independents.” Electoral 
Studies 28 (December): 562–572.

Wattenberg, Martin. 1984. The Decline of American Political Parties. Cambridge, MA: 
Harvard University Press.

James Vike is an associate professor of political science and director of the Master of 
Public Administration program at Widener University. He also serves as campus program 
director for Widener’s affiliation with Project Pericles. His research interests range from 
the study of bureaucratic politics to political participation and engagement. His publica-
tions include articles in COMMONWEALTH and Politics & Policy.




