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How Policy Influenced the Partisan Divide over Voting by Mail

The 2020 election opened up a big chasm between the parties in the use of mail-in ballots; 58% of Democrats voted by mail, compared to 29% of Republicans.  In previous years, there was little-to-no partisan difference in voting by mail.  

This partisan gap was stoked by the rhetoric of Donald Trump, who claimed that mail ballots were “out of control,” and that of his supporters, such as former Attorney General William Barr, who said that mail ballots would “open the floodgates to fraud.” State Republican leaders often followed suit, denying that there was anything special about the 2020 election that called for more liberal mail ballot laws.  For instance, Texas Lieutenant Governor Dan Patrick claimed expanding vote by mail for people under 65 to be ludacris, saying that, “people under 65 are more at risk of dying in a car wreck on the way to vote than they are from dying from contracting COVID-19 when voting.

On the other side of the aisle, Democrats actively sought to expand opportunities for voters to cast ballots before Election Day.  In her 2020 speech at the Democratic convention, Michelle Obama famously declared, “We’ve got to request our main-in ballots right now, tonight, and send them back immediately and follow-up to make sure they’re received.”  Democratic state officials with responsibility for running the election were often the most active and vocal in encouraging voting by mail.  For instance, Jim Condos, Vermont’s Secretary of State, said that “voting by mail is simple, safe and secure” and was the obvious choice for 2020. 

There were exceptions to these partisan divisions, to be sure.  Washington’s Republican Secretary of State Kim Wyman defended her state’s long history of mailing every registered voter a ballot and emphasized her confidence in the security measures in place for voting by mail.  

Still, voting in person became the “Republican thing to do,” while voting by mail was seen as the Democratic opinion.

Partisan rhetoric wasn’t the only part of this story, however.  Some states retained high barriers to using mail ballots while others made it easy, or at least easier than in the past.  How did these policy choices contribute to the big difference in the usage rates of mail ballots by Republicans and Democrats in the midst of the partisan rhetoric that was swirling around?

Image description: A color-coded map shows which states chose what policy approach regarding vote by mail in 2020. The states are specified below.

For the first time in American history, the most common way of voting in 2020 was to receive a ballot by mail. This increase in mail-ballot use was aided by states expanding eligibility of who could request a mail-in ballot, to mitigate the spread of COVID-19. But while voting by mail became easier in 2020 nationwide, there were exceptions. Many states already allowed any voter to request a mail ballot for any reason or already mailed every registered voter a ballot.  In response to COVID, five additional states and D.C. decided to mail ballots to all registered voters.  For those that required an excuse to request a mail ballot, most eliminated the excuse requirement or allowed voters’ concerns over COVID-19 to be a valid excuse for requesting a ballot.  Still, five states held firm, and continued to impose significant restrictions on absentee ballots.

Needing a non-COVID excuse vs. Vote by Mail for All

In this analysis, I zoom-in on the states that were at the extremes of vote-by-mail policy in 2020, focusing on three categories of states: 

  • Voters need a non-COVID excuse : Indiana, Louisiana, Mississippi, Tennessee, and Texas. These states did not allow COVID-19 to be a reason for voting by mail, and retained traditional excuse requirements, such as being out of town or infirm.
  • All Voters Mailed a Ballot as an Emergency Measure: States such as California, Montana, Nevada, New Jersey, and Vermont sent all voters a mail-in ballot automatically as an emergency measure, but still offered in-person voting.
  • All Voters Mailed a Ballot as Part of Permanent Policy:  Colorado, Hawaii, Oregon, Utah, and Washington were in this category.. These states mailed all registered voters a ballot, and had planned to do so before COVID-19 arose as a concern.

The empirical question I address is simple: was the partisan gap in using mail ballots greater in states that restricted it the most, or the states that made it easy?

Partisanship, Voting Mode Choice, and Policy

Figure 2, below, illustrates whether policy has a neutralizing effect on partisan decisions to vote by mail or if it did not by comparing the party breakdown of vote by mail versus the overall party breakdown of the electorate in each group of states. For the All Voters Mailed a Ballot as Part of Permanent Policy states , the vote by mail party breakdown mirrors the statewide party breakdown. Partisans don’t really have a choice whether to vote by mail or not in these states since they conduct all mail elections, so this outcome is expected. In the All Voters Mailed a Ballot as an Emergency Measure category, there are more Democrats opting to vote by mail than the All Voters Mailed a Ballot as Part of Permanent Policy states, however the divide is smaller than anticipated.

Image description: Party Breakdown vs. Vote by Mail Party Breakdown for different policies. This graph shows a grouped line chart for each state grouping. Each grouping of lines shows the party breakdown for those who voted by mail and the overall fraction of the electorate represented by each party. The goal of this graph is to compare the statewide party breakdown to the the vote by mail party breakdown to see if the vote by mail breakdown mirrors the party breakdown.

Interestingly, however, in the voters need a non-COVID excuse states category, the partisan divide is still notable; in fact, it strongly skewed Democrat when it comes to choosing voting by mail. If we turn to focus on specifically how many Democrats voted by mail versus how many Democrats there are statewide, as the policy spectrum moves from more progressive to more conservative, the gap between these percentages widens; in the most conservative policy environments, we witness the greatest partisan skew in vote mode choice.

Age, Voting Mode Choice, and Policy

Age, in addition to partisanship, was one of the greatest predictors of voting mode choice. Given that, I was also eager to see if the distribution of age of those who voted by mail was spread more evenly across ages in states with more restricted voting mode choice.

Image description: Vote by Mail Breakdown by Age Group. For each state grouping, the graph displays the percentage of the people who voted by mail by the different age breakdowns.The graph shows what percentage of vote by mail voters were in the different age buckets for the various state policies.

The above figure shows the age breakdown for voters who opted to vote by mail by the different state policy categories. For all policy categories, voters over 65 were more likely to vote by mail.  However, this age gap becomes more pronounced as we move from the permanent all-mail states to those that retained their strict excuse requirements in 2020.  This difference is especially stark in the states that still required an excuse.  Many of these states had policies that allowed older voters to request mail ballots.


The partisan divide over the use of mail ballots was stark in 2020, both in terms of the rhetoric of politicians and the behavior of voters.  Still, as we see here, policy choices made at the state level served to expand and contract those differences.  Mailing a ballot to all registered voters closed the partisan gap dramatically, but not entirely. (It probably helped that state leaders of both parties had long championed voting by mail in these states.)  Even when ballots were mailed to all registered voters, older voters were more likely to avail themselves of the option, but the age gap was especially large where states foreclosed the mail-ballot option to all but a small fraction of voters, including the elderly.  

Republicans who were automatically mailed ballots in nearly a dozen states could have chosen to vote in person, and many did, but most didn’t.  Thus, one consequence of expanding access to mail ballots was to create a more uniform experience for voters across the partisan divide, which is one under-appreciated result of how adapting to COVID affected the experience of voters.

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Joelle Gross is a Senior Research Support Associate at the MIT Election Data + Science Lab. Joelle joined the Lab in July 2021 after graduating with a B.A. from the University of Pennsylvania.

Topics Vote by mail and absentee voting