Voters are more likely to be split on the issue of mail-in voting along party lines than ever before, in part due to COVID-19, according to a report published Tuesday by a UC San Diego-led political science research team.
According to the report, written by the UC Office of the President-funded New Electorate Project, before the pandemic, there was no difference in the rates at which Democratic and Republican voters cast their ballots by mail or in-person.
However, based on nationally representative surveys conducted this spring and summer, researchers report a significantly greater preference for mail, or absentee, ballots among Democrats than Republicans. The researchers document for the first time a partisan gap in stated preferences in April 2020. By June, that gap had doubled — from a 10% difference in April to a 20% one in June.
The gap was even wider among those exposed to scientific projections about the COVID-19 pandemic, with Democrats expressing even greater preferences for mail ballots while Republicans were unaffected.
The findings are published in the Proceedings of the National Academy of Sciences.
After finalizing the paper, the research team — which includes researchers from UC San Diego, UC Riverside and USC — continued to survey America's eligible voters. The partisan gap, they say, has continued to grow: By late August, more than half of Democrats but less than a quarter of Republicans said they personally preferred to vote by mail.
"A serious partisan divide has opened up on preferences for voting by mail and has grown from a gap to a gulf over the past several months," said Thad Kousser, a UC San Diego professor of political science, senior author on the study and the New Electorate Project's principal investigator.
Personal preferences aside, there is bipartisan support for making mail ballots available to all voters who want them.
"Despite the polarization, we see support across the board for making voting more accessible," said Mackenzie Lockhart, lead author on the study and a political science doctoral candidate at UC San Diego. "In all our surveys, a majority of Republicans and Democrats supported not only making vote-by-mail ballots available to anyone who wants them, but also sending ballots directly to every registered voter, regardless of how they intend to vote."
Kousser noted that policies allowing any voters who request absentee ballots to cast their vote this way are in place in most states, including nearly every "swing state" in the presidential election.
The researchers attribute the growth in the partisan divide to two things: signals from partisan elites in both parties and Republican partisans' distrust in science and experts.
"Republican and Democratic lawmakers have staked out very different positions on voting by mail and voters have begun to notice," Lockhart said. "But on top of that, our evidence suggests that voters' views on COVID-19 are probably also polarizing the issue. We found that scientific predictions about the COVID-19 pandemic had much smaller effects on Republicans than Democrats and contributed to a larger gap between partisans."
Each survey was conducted with more than 5,600 Americans of voting age.
What remains an open question is whether there will now also be a partisan difference in actual voting behaviors. Also an open question: Will this gap affect the outcomes of the 2020 U.S. presidential election?
"We don't know what will happen in November, and if things go smoothly with both voting methods, then the partisan differences we found might not matter," Lockhart said. "But, based on our results, if either mode of voting — in-person or by mail — ends up not running smoothly, that's when these differences in how partisans want to vote could matter."
Lockhart said potential complications could include a spike in infection rates making voting in person more difficult, or delays in the mail leading to those ballots arriving after the deadline.
