Split-ticket voting
Split-ticket voting, also known as ticket splitting, refers to the electoral practice in which a voter selects candidates from different political parties for distinct offices on the same ballot, rather than supporting a single party's slate across all races.[1] This form of voting has been most prominently studied and observed in the United States, where ballots often combine federal, state, and local contests, allowing voters to mix partisan choices such as supporting one party's presidential candidate while backing another for congressional or gubernatorial seats.[2] Historically prevalent from the mid-20th century through the 1990s, split-ticket voting facilitated divided government outcomes, where control of the executive and legislative branches split between parties, often yielding policy compromises or institutional gridlock as causal mechanisms for balancing power.[3] Empirical analyses of aggregate election data reveal its peak incidence during periods of weaker partisanship, with rates exceeding 20-30% in presidential-congressional alignments in the 1970s and 1980s, driven by candidate-specific evaluations over strict party loyalty.[4] In recent decades, however, split-ticket voting has sharply declined to near-historic lows, with party-line voting dominating due to intensified polarization, nationalized campaign messaging, and structural factors like closed primaries that reinforce partisan cues.[5] For instance, in the 2020 election, ballot-level data from battleground states showed split-ticket rates below 2% among partisans for presidential and congressional races, underscoring a causal shift toward uniform partisanship that minimizes cross-party deviations.[6] This trend has notable implications, reducing the likelihood of divided government and amplifying unified party control, which can accelerate legislative agendas but also heighten risks of policy overreach absent internal checks.[4] Despite its diminished prevalence, split-ticket voting persists in select contexts, such as state and local races where personalized candidate appeals override national party brands, and it continues to intrigue scholars for evidencing residual voter pragmatism amid dominant ideological sorting.[7]Definition and Fundamentals
Core Definition
Split-ticket voting refers to the electoral behavior in which a voter selects candidates from more than one political party for different offices contested in the same election.[1] This contrasts with straight-ticket voting, where all selections align with a single party's candidates, and typically arises in systems featuring multi-office ballots that allow independent choices per race.[2] The phenomenon presupposes ballot designs permitting granular selection, as in the United States, where federal, state, and local partisan contests often appear together, facilitating cross-party choices without mechanical constraints like party-line levers.[8] Empirical measurement often relies on aggregate precinct data or validated voter surveys, revealing rates that have varied historically but generally indicate voters prioritizing candidate qualities or issue alignments over pure partisanship in specific contests.[9]Distinction from Straight-Ticket Voting
Straight-ticket voting refers to the practice in which a voter selects candidates from only one political party across all partisan offices on a ballot.[10] This behavior aligns with consistent partisan loyalty, often facilitated in certain U.S. states by a ballot mechanism allowing a single mark or electronic selection to cast votes for an entire party's slate of candidates, thereby streamlining the process and reducing the need for individual race-by-race decisions.[11] As of 2023, only six states—Alabama, Indiana, Kentucky, Michigan, Pennsylvania, and South Dakota—offered this straight-ticket option on ballots, though voters in other jurisdictions can still engage in straight-ticket behavior by manually selecting same-party candidates for each office.[10] In direct opposition, split-ticket voting occurs when a voter chooses candidates from multiple political parties for different offices within the same election, such as supporting a Democratic presidential candidate and a Republican congressional candidate.[1] This approach necessitates deliberate, office-specific selections without the efficiency of a party-wide vote, highlighting voter independence from strict party lines and potentially reflecting evaluations of individual candidate qualifications, policy positions, or local issues over blanket partisanship.[12] The primary distinction between the two lies in partisan consistency and ballot mechanics: straight-ticket voting emphasizes uniformity and expediency, often reinforcing party cohesion and down-ballot coattails effects, while split-ticket voting underscores selective cross-party support, which can dilute party discipline and contribute to divided government outcomes, as observed in U.S. elections where congressional majorities have opposed the presidency.[10][1] Where straight-ticket options exist, their use correlates with higher rates of uniform party voting, whereas their absence or voter opt-out encourages more split-ticket instances by requiring explicit choices per race.[11] This behavioral divide has measurable impacts on electoral outcomes, with straight-ticket dominance linked to stronger partisan sweeps in state legislatures and split-ticket patterns associated with ideological moderation or protest voting.[12]Measurement and Data Challenges
Measuring split-ticket voting poses significant challenges due to the secret ballot, which precludes direct observation of individual voter choices across multiple offices in most jurisdictions. In the United States, where the phenomenon is most studied, precinct-level aggregate election returns are the primary data source, requiring statistical techniques like ecological inference (EI) to estimate the proportion of voters supporting candidates from different parties for different races, such as presidential and congressional contests. These methods, including Gary King's EI algorithm, infer individual-level behavior from marginal vote totals but rely on assumptions of parameter constancy across precincts and specific distributional forms, such as the truncated bivariate normal, which are frequently violated in real data.[13] A core limitation is aggregation bias, where split-ticket rates correlate with precinct characteristics like presidential vote shares, leading to systematically skewed estimates. Simulations demonstrate that EI can produce results deviating by over 25 standard errors from true values (e.g., estimating 0.5 split rates as highly biased), while ordinary least squares regressions yield implausible negative proportions, such as -10.8% of one candidate's voters supporting an opposing party. Tomography diagnostics often reveal uninformative bounds (e.g., [0.28, 0.91] for certain parameters), indicating insufficient data to constrain estimates reliably, particularly in small or homogeneous precincts. Multi-stage estimation further compounds errors, undermining district-level inferences.[13] Survey-based alternatives, drawing from self-reported data like the Cooperative Election Study, face recall inaccuracies, social desirability bias favoring partisan consistency, and overestimation of split-ticket rates by an average of 2.14 percentage points, with root mean square errors around 6.18 points. Validation against anonymized cast vote records in states like South Carolina (2010-2018) and Maryland (2016-2018) confirms higher errors for state-level races (standard deviation ~6.9 points) compared to national dyads (~3.8 points), attributed to smaller samples and temporal distance from elections. Aggregate methods also risk ecological fallacy, overestimating splits relative to individual-level surveys (e.g., 25% vs. lower survey figures in some contexts), as they cannot disentangle voter-specific motivations without additional assumptions like demographic isomorphism.[14][15][13] These issues are exacerbated in diverse or low-information settings, where varying split rates across subgroups (e.g., by race or turnout) violate EI's independence assumptions, leading to unreliable national trends. While rare access to unit-level ballot images in select jurisdictions provides "ground truth" for validation, such data remain exceptional and non-generalizable, highlighting the field's dependence on imperfect proxies that may conflate measurement artifacts with behavioral shifts, such as the observed decline in split-ticket voting since the 1980s.[14]Historical Evolution
Early Instances and 19th-Century Roots
Prior to the widespread adoption of the secret Australian ballot in the late 1880s, split-ticket voting in the United States was constrained by the dominant party ballot system, which emerged in the 1830s and 1840s during the Second Party System. Political parties produced and distributed pre-printed tickets listing their slate of candidates for multiple offices, distributed openly at polling places by party workers, which incentivized voters to deposit entire straight tickets to avoid scrutiny, intimidation, or loss of patronage benefits.[16][17] This system, replacing earlier oral voting and handwritten ballots, bundled candidates to reinforce party discipline, but it did not eliminate splitting entirely.[18] Early instances of split-ticket voting relied on rudimentary alterations to these party tickets, such as "scratching"—crossing out disfavored names and writing in alternatives—or applying "pasters," small slips of paper with opposing candidates' names pasted over the original ticket. These practices, though feasible, were visible to onlookers and poll watchers, exposing splitters to social pressure, bribery reversal, or violence in a non-secret voting environment. Scratching and pasters were documented in urban elections from the 1850s onward, particularly in competitive locales like New York City, where nativist American Party challenges to Democrats and Whigs prompted some voters to mix tickets for local offices while supporting presidential nominees from another party.[17][19] By the 1880s, as party competition intensified amid third-party movements like the Greenback and Prohibition parties, scratched ballots gained attention in national elections. In the 1884 presidential contest between Grover Cleveland and James G. Blaine, newspapers reported instances of voters scratching electoral tickets to swap presidential electors or congressional candidates across party lines, reflecting occasional prioritization of individual candidate appeal over strict partisanship. However, such deviations remained infrequent, with estimates suggesting split-ticket rates below 10% in most jurisdictions before reforms, as party tickets' design and distribution minimized deviations to preserve organizational control.[20][21] The 19th-century roots thus lay in these imperfect mechanisms amid a system favoring party unity, setting the stage for expansion only after the Australian ballot—first adopted in Massachusetts in 1888 and spreading nationwide by 1896—introduced government-printed, secret ballots that shielded voters from observation and simplified mixing choices without physical alterations.[21][22]Peak Prevalence in the Mid-20th Century
Split-ticket voting reached its zenith in the United States during the mid-20th century, particularly from the 1950s through the 1970s, as measured by aggregate election outcomes and survey data on voter behavior. This era featured frequent divergences between presidential preferences and down-ballot choices, driven by regional cross-pressures, candidate-centered campaigns, and relatively weaker national party cohesion compared to earlier or later periods. For example, in the 1964 presidential election, 14 states produced split presidential-Senate outcomes, the highest in the postwar period, with Republican senators elected in states overwhelmingly won by Democrat Lyndon B. Johnson.[23] Similarly, the 1968 election saw 16 such split states, largely in the South where voters supported independent George Wallace for president but returned Democratic senators amid lingering regional loyalties.[24] At the congressional district level, splits were commonplace, reflecting broader voter willingness to cross party lines. In 1952, 86 House districts diverged from presidential results, a figure that rose over subsequent decades as party tickets weakened.[4] By 1972, approximately 193 districts—nearly 44% of the total—split their votes between Republican Richard Nixon and Democratic House candidates, with Southern districts accounting for a disproportionate share due to conservative Democratic incumbency.[25] American National Election Studies (ANES) data corroborate this, showing elevated rates of individual president-House ticket-splitting in the 1950s and 1960s relative to post-1980s declines, with splits often exceeding 20% in key cycles before partisan realignments intensified.[26] This peak contrasted with the more uniform straight-ticket patterns of the early 20th century and the sharp drop-off after the 1970s, attributable to factors like the erosion of machine politics and the rise of ideological sorting. Scholars such as David Kimball observe that split-ticket prevalence climbed from the 1950s, fostering frequent divided government—such as Democratic Congresses during Republican presidencies—but waned as parties polarized along national lines.[4] Overall, mid-century data underscore a electorate more pragmatically detached from strict partisanship, enabling outcomes where local or personal candidate appeal trumped national party cues.[24]Decline from the 1980s Onward
Split-ticket voting in the United States experienced a marked decline beginning in the 1980s, with the share of voters casting ballots for candidates from different parties in presidential and congressional races dropping from 27% in 1980 to 17% in 2000, according to American National Election Studies (ANES) respondents.[4] This erosion extended to aggregate outcomes, as the number of split congressional districts—those supporting opposing parties for president and House—fell to 86 in 2000, the lowest since 1952, and further to just 26 out of 435 in 2012.[25] At the state level, split presidential-Senate outcomes, which affected 11 of 34 states in 1992, became increasingly rare, reflecting a broader nationalization of electoral behavior where local races aligned more closely with presidential preferences.[27] Several interconnected factors drove this decline, foremost among them the intensification of partisan polarization. Ideological distances between congressional parties, as quantified by DW-NOMINATE scores, widened substantially from 0.39 in 1972 to 0.87 in 2000, elevating the salience of party labels and diminishing incentives for cross-party support.[4] Concurrently, the proportion of strong partisans rose from 32% in 1976 to 41% in 2000, while the share of voters perceiving significant differences between parties increased from 55% to 79% over the same period, fostering a view of elections as zero-sum interparty contests rather than evaluations of individual candidates.[4] The contraction of local media coverage exacerbated these trends by reducing voter exposure to candidate-specific information, leading to greater reliance on national partisan cues. Empirical analysis of the mid-20th-century introduction of commercial television, which eroded local newspaper revenues and coverage, demonstrates that affected areas exhibited higher rates of straight-ticket voting across national and local races, with persistent effects into recent decades.[28] Closures of local newspapers in subsequent years correlated with increased political polarization and fewer split-ticket voters, as diminished scrutiny of district-specific issues allowed national narratives to dominate local contests.[29] This dynamic, combined with rising negative partisanship—where aversion to the opposing party outweighs candidate appeal—has entrenched straight-ticket tendencies, rendering split voting a marginal phenomenon by the 2020s.[30]Geographic Prevalence
United States Focus
Split-ticket voting in the United States occurs nationwide but varies geographically, with higher incidences typically observed in politically competitive battleground states where cross-party voter defections are more feasible due to balanced partisan competition. In less polarized, solidly partisan regions such as the Deep South or rural Plains states, straight-ticket voting predominates, reflecting stronger local party loyalty and fewer incentives for splitting. Aggregate election outcomes serve as a proxy for underlying voter behavior, as individual-level data from cast vote records is limited to select jurisdictions due to ballot secrecy.[31][25] In 2018, 14 states produced split-ticket results in statewide races, electing executives or legislators from opposing parties, compared to only 8 states in 2020, indicating geographic concentration in swing areas amid national polarization trends. Battleground states like Arizona, Nevada, Pennsylvania, and Wisconsin have shown elevated splitting in recent cycles; for instance, in the 2024 election, approximately 7.9% of Donald Trump voters in Arizona supported the Democratic Senate candidate, while 4% of Trump voters in Wisconsin backed Democrat Tammy Baldwin. Such patterns contrast with minimal splitting in non-competitive states like California or Texas, where partisan majorities exceed 10-15 points in presidential races.[31][32][33]| Election Year | States with Split Statewide Outcomes (Examples) | Notes |
|---|---|---|
| 2018 | 14 states (e.g., Florida, Michigan, Ohio) | Higher due to midterm dynamics and local factors.[31] |
| 2020 | 8 states (e.g., Georgia, North Carolina) | Decline amid presidential-year coattails.[31] |
| 2022 | 6 states (e.g., Pennsylvania, Wisconsin for Senate/Governor splits) | Focused on Rust Belt competitiveness.[34] |
| 2024 | At least 3 battlegrounds (e.g., Arizona, Nevada, Wisconsin) | Trump voters drove Republican-to-Democratic Senate splits at 3-8%.[32][35] |