Restricting mail-in voting reduces voter participation in U.S. elections

What's this about?

People disagree about whether limits on mail voting make fewer people vote in U.S. elections.

The answer can change by voter, rule, and type of election.

What supporters say

• Mail voting helps people who lack rides, have busy jobs, care for kids, or have health limits.
• Mail voting gives some people a key way to vote when voting in person feels hard.
• Rules about dates, forms, signs, and mailing can make voting harder or cause some votes to fail.

What critics say

• Mail voting often makes only a small change in the total number of people who vote.
• A place with much mail voting and high voting rates does not prove mail voting caused those high rates.

How to read this

The number of points on each side does not show which side is right; strong proof matters more.

The bottom line

Limits on mail voting can lower voting for some people, especially those facing bigger blocks.

But the total drop may stay small, and we are not sure mail limits always lower voting.

The claim that restricting mail-in voting reduces participation is partly supported, but not universally true. The effect depends on who is affected, what voting options replace mail ballots, and how important the election is to voters.

The case for

Mail voting removes practical obstacles that can otherwise keep people from the polls. It reduces the need to travel, take time off work, arrange child care or find accessible transportation. Restricting that option therefore removes a channel through which some voters can participate. 1

The strongest direct evidence comes from a peer-reviewed study of Washington state’s gradual shift to all-mail elections. It found that turnout increased after the change, although the size of the increase varied by the election and by voter group. The study tracked turnout before and after the reform rather than simply comparing states with different voting systems, making it relevant to the question of whether expanding mail access can cause higher participation. 2

The effects may be especially important for voters who face greater barriers to in-person voting. Survey research finds that voting obstacles are not experienced equally across demographic groups. Research on accessibility also identifies remote voting as an important option for people with disabilities. These findings suggest that a statewide turnout average could miss larger effects among voters with limited transportation, inflexible work schedules, caregiving duties or mobility constraints. (see Figure 2)

Restrictions can also create administrative problems, not just travel and scheduling costs. Deadlines, ballot-request rules, signature requirements and the process of returning a ballot can determine whether a vote is successfully counted. A study of prepaid return postage found that even a seemingly small mailing burden can affect turnout, suggesting that additional administrative steps may discourage voting or cause ballots to be rejected. 3

The case against

The evidence does not show that every restriction produces a large drop in overall turnout. Studies from California and Colorado found limited or modest aggregate effects from mandatory or expanded mail voting, along with substantial movement by voters between mail and in-person methods. Where in-person voting remains convenient, restricting mail may change how existing voters cast their ballots without greatly changing how many people vote. 4

Nor does the high level of mail voting and turnout during the 2020 election prove that mail access caused the increase. That election also featured unusually high political interest, extensive mobilization and pandemic conditions. Because all of those factors changed at once, national turnout figures cannot isolate the effect of mail voting alone. 5

The result depends heavily on what replaces mail voting. Accessible early voting, sufficient polling places, long hours and reliable registration systems can allow voters to switch methods. In those circumstances, the statewide effect of a restriction may be small. By contrast, when mail is the only practical option for some people, the same restriction is more likely to reduce participation.

Election importance matters as well. Evidence from Oregon and other all-mail elections suggests that convenience-related effects can be larger in lower-turnout, lower-salience elections, while Washington research also found differences across election settings. That makes broad claims about every U.S. election difficult to sustain. (see Figure 3)

The bottom line

The evidence favours a conditional version of the claim, not a universal one. Mail access clearly lowers voting costs, and some restrictions will burden particular voters. There is also credible evidence that expanding all-mail voting can increase turnout in at least some settings. 12

But the evidence is weaker on the size of the overall statewide effect. When voters have accessible alternatives, many may simply switch from mail to in-person voting, leaving total participation little changed. The likely effect of a restriction therefore ranges from modest or negligible overall to a meaningful decline where mail is essential for affected voters. Confidence is high that restrictions can create unequal burdens; it is lower that any particular restriction will reduce turnout by a predictable amount in every election.