Mail Balloting in the Classroom

Michael McDonald
7 min readAug 13, 2020


My purpose in this post is to provide ideas how to have a timely classroom discussion on the administration of mail balloting. I draw upon my experience of teaching classes on election law, election administration, and election data science to provide discussion points and resources for teachers who wish to incorporate mail balloting into their classrooms. The materials provided are suitable for a range of class levels and student skills.


  1. A brief introduction to mail balloting — a short history of mail balloting
  2. Resources — suggested popular news articles on mail balloting and a guide to state laws
  3. Case studies — state reports on ballot rejection reasons to stimulate discussion on how state policies result in
  4. Election data science — Online real-time mail ballot analyses and data resources to spark class discussion. Programming skills are required for students who wish to do their own analyses.

A Brief Introduction to Mail Balloting

The coronavirus has changed many of the ways our society functions, including the way we run elections. A fundamental change to election administration is the promoting the usage of mail balloting.

Mail balloting extends at least back to the Revolutionary War, when soldiers sent hand-written ballots for loved ones to vote in their stead. Kansas and Missouri were the first states to adopt excuse-required mail balloting in 1911, where election officials would send ballots to voters to cast by mail. In 1974, Washington became the first state to allow any eligible vote to request and cast a mail ballot, what is known as no-excuse absentee voting, and the number of adopting states have increased since.

Monterrey, California because the first local government to run an election entirely by mail in 1977. Localities across the country began experimenting with this approach because mail ballot elections are cheaper to run than polling-place elections, and because of potential voter turnout increases (often necessary to achieve required participation thresholds for local tax and bond measures). In 1993, Oregon became the first state to hold a statewide all-mail ballot election for a ballot initiative, and their voters formally adopted it for all elections via a 1998 ballot initiative.

It should be mentioned that “all-mail” ballot election is a bit of a misnomer. All registered voters are sent a mail ballot. Voters may return their ballots by mail, in-person at election locations or special drop-boxes, or vote in-person if desired or required.

With the expansion of mail balloting, the percentage of voters casting a mail ballot has steadily increased over time. According to the Census Bureau’s Current Population Survey and Voting Registration Supplement, 23% of all voters cast a mail ballot in the 2018 general election.

Mail ballots are an attractive option to administer an election held in the midst of a pandemic, so that people are keep socially distant. For the November 2020 election, California, Colorado, Hawai’i, Oregon, Utah, Vermont, Washington and the District of Columbia will hold all-mail ballot elections. Vermont and DC are doing so on an emergency basis and California is accelerating their planned transition to all-mail elections. More election officials are encouraging mail balloting, even if they are not fully adopting all-mail ballot elections, by sending mail ballot applications to registered voters. A few states have decided not to expand mail balloting by only offering absentee voting to those who qualify for narrow excuse reasons.

Recommended supplemental class readings

Some of these readings may be gated.

Suggested exercise: Select two states, choosing two different states using the New York Times review as a guide. Analyze these states’ laws using the National Conference of Legislature’s review. How do the two states administer mail balloting in similar and different ways? Do you think their laws promote more or less mail balloting? Do you think their laws result in more or fewer rejected mail ballots?

Mail Ballot Rejections

A few states provide reports on the number of rejected mail ballots, and the reasons ballots are rejected, in their 2020 presidential primary. Some of these reports can be found online, some may be provided upon request, and some may be constructed from analyses of individual level data (described in the next section).

I provide selected ballot rejection statistics for some states. (I also placed these statistics in a Google Doc.) Have students think critically about these rejection reasons. Why might some states have a rejection reason, but another does not? Why might a state have more or fewer ballots rejected for the same reason?


California provided to me their mail ballot rejection reasons. Here are summary statistics of some of their frequent rejection reasons.

California ballot rejection reasons

Discussion question:

  • California had a total of 102,428 rejected mail ballots, more than other states. Why?


Colorado provided to me their mail ballot rejection reasons. Here are summary statistics of some of their frequent rejection reasons.

Colorado ballot rejection reasons

Discussion question:

  • Why do some states, like California, report a “ballot was not received on time” but others, like Colorado, report “Received After 7pm on Election Day”?


Michigan provided to me an individual list of ballot rejection reasons for their 2020 primary. Here are summary statistics of some of their frequent rejection reasons.

Michigan Ballot Rejection Reasons

Note there is a subtle, but important, distinction between a rejected and cancelled ballot. A person who “VOTED AT THE POLLS” had their ballot cancelled, not rejected.

Discussion question:

  • What other types of “rejected” ballots might properly be considered “cancelled ballots”?


Minnesota provided to me an individual list of ballot rejection reasons for their 2020 primary. Here are summary statistics of some of their frequent rejection reasons.

Minnesota Ballot Rejection Reasons

Discussion questions:

  • Why does Minnesota reject absentee ballots for no witness signature or notary stamp?
  • Should states require a witness signature or a notary stamp in the midst of a pandemic?


The Washington 2020 Presidential Primary Reconciliation Report has information on rejected ballots by county. You can download prior year reports, too.

Washington Ballot Rejection Reasons

Discussion Questions:

  • What were the most frequent reasons why mail ballots are rejected?
  • What policies might you promote to reduce the number of rejected mail ballots? For example, would having a drop box where voters can return their ballots directly to election officials mitigate mail ballot delays and ballots rejected for being returned late?

Mail ballot analyses

Two states — Georgia and North Carolina — post individual level mail ballot data online. These databases include the date a voter requested a mail ballot, the date election officials sent the ballot, the date the voter returned the ballot, and the disposition of the ballot, whether a ballot was rejected or accepted and the reason for a rejection. Both states provide the names, addresses, and counties voters’ reside in. North Carolina further provides demographic characteristics, such as age, gender, race, and party registration.

Students with sufficient programming skills can analyze and visualize these data, and I recommend this as a great class project for a programming or statistics class. You can also follow daily analyses of these data at Georgia Votes and Old North State Politics. I provide national coverage of early voting activity at the United States Elections Project.

These individual level ballot data for current and past elections are available at:

Students can analyze and visualize mail ballot patterns by geographic regions and demographic groups. There are a number of questions students may address, such as:

  • Is mail ballot usage higher in some counties compared to others?
  • Who are the voters requesting and casting mail ballots?
  • Are the characteristics of the people casting mail ballots changing over time?
  • Who hasn’t returned their ballot, or who has a ballot rejected?
  • Are there unusual patterns that might indicate COVID-related problems, such as lower administrative activity in particular counties that may have had their office temporarily shut down?
  • Why do election officials issue multiple ballots to the same voter?
  • What are the implications for election administrators as the number of mail in ballots is expected to greatly increase for the upcoming election?

These are just some questions. My students have devised several innovative projects, some that have led to academic publications! I’d encourage weekly student presentation updates, or simply visiting the tracking websites can also stimulate class discussion. In my less technically demanding classes, I often discuss the latest early voting numbers while we wait for class to begin.

I recommend that students use statistical software, such as R. A free introductory textbook, R for Data Science, is available on-line. I encourage students to post their findings on a blog using R Markdown, which can provide prospective employers with example work-product.



Michael McDonald

Professor at the University of Florida who specializes in American elections