How we did this

Pew Research Center conducted this study to understand Americans’ voting behavior in the 2020 election. Whenever possible, respondents to the survey were presented with the House and Senate candidates that will appear on their ballots by using information about their locations.

Some races do not include candidates of both major parties (for example, a few districts in California have two Democratic and no Republican candidates). Excluding these handful of races where there are not two major party candidates running does not meaningfully impact the conclusions of this report, but they have been included in the analyses presented here.

Everyone who took part in this survey is a member of Pew Research Center’s American Trends Panel (ATP), an online survey panel that is recruited through national, random sampling of residential addressees. This way nearly all U.S. adults have a chance of selection. The survey is weighted to be representative of the U.S. adult population by gender, race, ethnicity, partisan affiliation, education and other categories. Read more about the ATP’s methodology.

Here are the questions used for the report, along with responses, and its methodology.

In an era of increasing partisanship, split-ticket voting continues to be rare in U.S. politics. With control of the Senate at stake on Nov. 3, just 4% of registered voters in states with a Senate contest say they will support Donald Trump or Joe Biden and a Senate candidate from the opposing party.

In voting for both the House and Senate, partisanship prevails. About eight-in-ten of voters (78%) say they will vote (or already have voted) for either Biden and the Democratic House of Representatives candidate (43% of all voters) or Trump and the Republican candidate (35% of all voters) in their congressional district.

Only 4% of registered voters say they plan to vote for Biden and the Republican candidate for House in their district or Donald Trump and the Democratic House candidate. This is little changed from four years ago. It is more common for voters to say they plan to vote for a third-party candidate for president (or less commonly, for the House) and a major-party candidate for the other race. Still, only 6% of voters say they plan to cast their ballots this way.

Similarly, among those living in states with Senate races, the largest share of voters say they plan to vote for both Biden and the Democratic Senate candidate (42%) or Trump and the Republican Senate candidate (38%) in their state. A recent analysis of U.S. Senate elections since 2012 shows how rare it is for a Senate race to go a different way from a state’s votes in presidential elections. In 139 regular and special elections for the Senate since 2012, 88% have been won by candidates from the same party that won that state’s most recent presidential contest.

This analysis of split-ticket voting is based on Pew Research Center’s recent national survey, conducted Sept. 30 to Oct. 5 among 11,929 U.S. adults, including 10,543 registered voters in which Biden garners support from 52% of registered voters and Trump is supported by 42%. The survey used information about respondents’ locations to present survey-takers with the names of the candidates running in each congressional race.

Modest demographic differences in split-ticket voting

Majorities of every major demographic group in the electorate are voting for the same party’s candidate in the presidential election and the congressional election in their district. The share of voters in any major demographic group that casts a ballot for both a Republican and a Democratic candidate in these elections is usually less than 5% across major demographic groups.

Straight-ticket voting mirrors presidential voting patterns. Men are more likely than women to vote for Republican candidates in both the House and presidential elections, while women are more likely to support Democratic candidates in both.

White voters are substantially more likely than voters of other racial and ethnic backgrounds to vote for Republican candidates in both the congressional and presidential elections.

The share of voters casting a straight-ticket Republican ballot in these elections increases steadily with age. Only 22% of Gen Z voters are voting this way, compared with nearly half (47%) of Silent Generation voters.

Gen Z and Millennial voters are also more likely than voters in older generations to support third- or fourth-party candidates for president; 13% of Gen Z voters favor non-major party candidates for either House or president, as do 9% of Millennial voters. Thus, larger shares of voters in these generations split their votes for president and the House. But just 3% of Gen Z voters and 4% of Millennials favor Biden and a Republican House candidate or Trump and a Democrat. That is comparable to the shares of older voters who divide preferences on a partisan basis in voting for president and the House.

Voters with a bachelor’s degree or more education are much more likely to vote a straight Democratic ticket in these races than are those with less education. There is no relationship between education and Republican-Democratic split-ticket voting; equal shares of voters (4%) across different levels of educational attainment vote this way.

Lower-engagement voters – those who say they have given less than “a lot” of thought to the presidential race – are more likely than others to split their tickets between the Republican and Democratic candidates in the presidential and congressional elections in their districts, though it is still very uncommon (6% of lower-engagement voters vs. 3% of those who are paying a lot of attention to the race).

These lower-engagement voters are much more likely to support minor-party candidates in either the presidential race or the congressional race in their district (14% of those who are paying less than “some” attention to the race vs. 5% of those who are paying “a lot” of attention).

Among all registered voters, Democrats hold an edge in congressional elections, with 46% of voters saying they will vote (or have already voted) for the Democratic candidate in their district and 40% saying they support the Republican candidate. About one-in-ten voters (11%) are not sure whom they will support.

Trump voters and Biden voters overwhelmingly say they support the same party’s candidate for the congressional race in their district (83% of each say they will support a candidate of the same party). Voters who support minor-party candidates for president are about evenly divided in their vote for the House of Representatives (29% support the Democrat and 31% support the Republican).

Trump supporters and Biden supporters living in districts with an opposite-party incumbent are slightly more likely to split their tickets than those living in districts with a same-party incumbent or an open-seat contest. Trump supporters in districts with Democratic incumbents and Biden supporters in districts with Republican incumbents are also more likely than those with same-party incumbents to say they are undecided in the congressional race.

Overall in states where there is a Senate contest, support for Senate candidates is roughly evenly divided. The share of voters supporting the Democratic candidate (45%) in their state is similar to the share supporting the Republican candidate (43%), and 8% of voters say they aren’t sure at this point whom they will support.

Similar to the elections for the House of Representatives, overwhelming shares of voters who are supporting Trump (88%) and Biden (84%) say they are also supporting the same-party candidate for Senate, while those who are supporting a minor-party candidate are more divided (27% support the Democratic candidate in their state and 35% support the Republican candidate).

Unlike in the House elections, there is less evidence that incumbency has any effect on split-ticket voting in these higher-profile Senate races.

This report is a collaborative effort based on the input and analysis of the following individuals:

Research team

Carroll Doherty, Director, Political Research Jocelyn Kiley, Associate Director, Political Research Andrew Daniller, Research Associate Bradley Jones, Research Associate Hannah Hartig, Research Associate Amina Dunn, Research Analyst Hannah Gilberstadt, Research Assistant Ted Van Green, Research Assistant Vianney Gomez, Research Assistant

Communications and editorial

Nida Asheer, Communications Manager Calvin Jordan, Communications Associate David Kent, Senior Copy Editor

Graphic design and web publishing

Peter Bell, Design Director Alissa Scheller, Information Graphics Designer Sara Atske, Associate Digital Producer

The American Trends Panel survey methodology

Overview

The American Trends Panel (ATP), created by Pew Research Center, is a nationally representative panel of randomly selected U.S. adults. Panelists participate via self-administered web surveys. Panelists who do not have internet access at home are provided with a tablet and wireless internet connection. Interviews are conducted in both English and Spanish. The panel is being managed by Ipsos.

Data in this report is drawn from the panel wave conducted Sept. 30 to Oct. 5, 2020. A total of 11,929 panelists responded out of 13,582 who were sampled, for a response rate of 88%. This does not include six panelists who were removed from the data due to extremely high rates of refusal or straightlining. The cumulative response rate accounting for nonresponse to the recruitment surveys and attrition is 5%. The break-off rate among panelists who logged on to the survey and completed at least one item is 0.8%. The margin of sampling error for the full sample of 11,929 respondents is plus or minus 1.5 percentage points.

Panel recruitment

The ATP was created in 2014, with the first cohort of panelists invited to join the panel at the end of a large, national, landline and cellphone random-digit-dial survey that was conducted in both English and Spanish. Two additional recruitments were conducted using the same method in 2015 and 2017, respectively. Across these three surveys, a total of 19,718 adults were invited to join the ATP, of whom 9,942 (50%) agreed to participate.

In August 2018, the ATP switched from telephone to address-based recruitment. Invitations were sent to a random, address-based sample of households selected from the U.S. Postal Service’s Delivery Sequence File. Two additional recruitments were conducted using the same method in 2019 and 2020, respectively. Across these three address-based recruitments, a total of 17,161 adults were invited to join the ATP, of whom 15,134 (88%) agreed to join the panel and completed an initial profile survey. In each household, the adult with the next birthday was asked to go online to complete a survey, at the end of which they were invited to join the panel. Of the 25,076 individuals who have ever joined the ATP, 13,582 remained active panelists and continued to receive survey invitations at the time this survey was conducted.

The U.S. Postal Service’s Delivery Sequence File has been estimated to cover as much as 98% of the population, although some studies suggest that the coverage could be in the low 90% range.¹ The American Trends Panel never uses breakout routers or chains that direct respondents to additional surveys.

Sample design

The overall target population for this survey was non-institutionalized persons age 18 and over, living in the U.S., including Alaska and Hawaii.

Questionnaire development and testing

The questionnaire was developed by Pew Research Center in consultation with Ipsos. The web program was rigorously tested on both PC and mobile devices by the Ipsos project management team and Pew Research Center researchers. The Ipsos project management team also populated test data which was analyzed in SPSS to ensure the logic and randomizations were working as intended before launching the survey.

Incentives

All respondents were offered a post-paid incentive for their participation. Respondents could choose to receive the post-paid incentive in the form of a check or a gift code to Amazon.com or could choose to decline the incentive. Incentive amounts ranged from $5 to $15 depending on whether the respondent belongs to a part of the population that is harder or easier to reach. Differential incentive amounts were designed to increase panel survey participation among groups that traditionally have low survey response propensities.

Data collection protocol

The data collection field period for this survey was Sept. 30 to Oct. 5, 2020. Postcard notifications were mailed to all ATP panelists with a known residential address on Oct. 2, 2020.

On Sept. 30 and Oct. 1, invitations were sent out in two separate launches: Soft Launch and Full Launch. Sixty panelists were included in the soft launch which began with an initial invitation sent on Sept. 30, 2020. The ATP panelists chosen for the initial soft launch were known responders who had completed previous ATP surveys within an average of six hours after receiving their invitation. All remaining English and Spanish panelists were included in the full launch and were sent an invitation on Oct. 1, 2020.

All panelists with an email address received an email invitation and up to two email reminders if they did not respond to the survey. All ATP panelists that consented to SMS messages received an SMS invitation and up to two SMS reminders. Interactive Voice Recording (IVR) reminder calls were made to 152 tablet households that previously provided consent to receive these reminders on Oct. 2, 2020.

Data quality checks

To ensure high-quality data, the Center researchers performed data quality checks to identify any respondents showing clear patterns of satisficing. This includes checking for very high rates of leaving questions left blank, as well as always selecting the first or last answer presented. As a result of this checking, six ATP respondents were removed from the survey dataset prior to weighting and analysis.

Weighting

The ATP data was weighted in a multistep process that accounts for multiple stages of sampling and nonresponse that occur at different points in the survey process. First, each panelist begins with a base weight that reflects their probability of selection for their initial recruitment survey (and the probability of being invited to participate in the panel in cases where only a subsample of respondents were invited). The base weights for panelists recruited in different years are scaled to be proportionate to the effective sample size for all active panelists in their cohort. To correct for nonresponse to the initial recruitment surveys and gradual panel attrition, the base weights for all active panelists are calibrated to align with the population benchmarks identified in the accompanying table to create a full-panel weight.

For ATP waves in which only a subsample of panelists are invited to participate, a wave-specific base weight is created by adjusting the full-panel weights for subsampled panelists to account for any differential probabilities of selection for the particular panel wave. For waves in which all active panelists are invited to participate, the wave-specific base weight is identical to the full-panel weight.

In the final weighting step, the wave-specific base weights for panelists who completed the survey are again calibrated to match the population benchmarks specified above. These weights are trimmed (typically at about the 1st and 99th percentiles) to reduce the loss in precision stemming from variance in the weights. Sampling errors and test of statistical significance take into account the effect of weighting.

The following table shows the unweighted sample sizes and the error attributable to sampling that would be expected at the 95% level of confidence for different groups in the survey.

Sample sizes and sampling errors for other subgroups are available upon request. In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.

Dispositions and response rates

© Pew Research Center, 2020