Apr 30, 2020 9:41 AM

The Weird Partisan Math of Vote-by-Mail

Research says that expanding mail-in voting doesn’t help Democrats. So why are Republicans so afraid of it?

Nothing illustrates the mixed-up politics of vote-by-mail better than the world’s most famous absentee voter declaring the practice corrupt. “Mail ballots are a very dangerous thing for this country, because they’re cheaters,” Donald Trump told reporters in early April, a few weeks after casting an absentee ballot in Florida’s primary. “They're fraudulent in many cases.”

With the timeline of the coronavirus pandemic still uncertain, it’s clear that the US needs a plan to allow people to vote in November without putting their lives at risk. The most obvious option is to let everyone cast their ballot by mail. But, as with so many things coronavirus-related, that idea has become polarized along partisan lines. A poll released this week by the Associated Press-NORC Center for Public Affairs Research showed 73 percent of Democrats in favor of allowing everyone to vote by mail, compared to just 46 percent of Republicans (and 59 percent of independents). In Washington, while congressional Democrats push to include funding to expand vote-by-mail in the federal coronavirus relief bills, some Republican officials, most notably Trump, decry the idea as a partisan power grab. “They had things, levels of voting that if you’d ever agreed to it, you’d never have a Republican elected in this country again,” the president told the hosts of Fox & Friends in March, referring to the Democrats’ proposals.

Read all of our coronavirus coverage here.

Trump was roundly ridiculed for suggesting that expanding vote-by-mail would hurt Republicans in November. The New York Times called it a “false claim,” declaring that “there is no evidence to back up the argument from the right that all-mail elections favor Democrats.” But the truth is a little more complicated.

Universal Vote-by-Mail Raises Turnout—but for Whom?

There are basically three categories of vote-by-mail in the US. The most restrictive level, found in seven states, is traditional absentee balloting, where voters have to give a reason why they can’t vote in person. Next is no-excuse absentee, where anyone can vote by mail but must request a ballot. About half of states have a version of that. Then there’s universal vote-by-mail, or “vote at home,” a system now used in five states—Colorado, Hawaii, Oregon, Utah, and Washington—plus many counties in California. The government automatically mails a ballot to every registered voter, and voters have about two weeks to mail the ballot back, or they can drop it off in person by election day.

Most of the research focuses on that last category. Vote-at-home made its general-election debut in Oregon in 2000, and five years later spread to neighboring Washington, where all but one county quickly opted in. (The last holdout joined in 2012.) Those two states now consistently have some of the nation’s highest turnout rates. So does Colorado, which adopted the system in 2014. Studies have long found a link between vote-by-mail and higher turnout. It’s easy to see why: When voting becomes more convenient, more people tend to do it.

Bringing in more voters is not an unalloyed good in the eyes of all politicians, however, so support for vote-by-mail has always had partisan twists—but which party is in support has varied over time and across states. In 1995, Oregon’s Republican-controlled legislature passed a bill enacting vote-at-home, only to have it vetoed by Governor John Kitzhaber, a Democrat. (Three years later, voters overwhelmingly approved the change through a ballot initiative.) Many Democrats worried it would help the other side. Absentee voting has long been a favorite of older, whiter, Republican-leaning voters. Phil Keisling administered the transition to vote-at-home as Oregon’s secretary of state in the 1990s and now chairs the National Vote at Home Institute, a nonpartisan organization that advocates expanding the reform. He recalled conversations with Democratic politicians who worried, “It’ll help rural white voters, and it won’t help our base, and it’s a bad idea.” Skittish Democrats saw confirmation of their fears in 2014, when, in Colorado’s first all-mail election, Republicans wiped out Democrats in statewide races.

Recent research has pushed the pendulum in the other direction. A 2017 study commissioned by the Washington Monthly, where I was an editor, and conducted by Amelia Showalter of Pantheon Analytics found that Colorado’s new system appeared to account for a 3.3 percent overall turnout increase in 2014, compared to a turnout model that was highly accurate but didn’t factor in new voting systems. That bump was overwhelmingly concentrated among younger and lower-propensity voters: the 18- to 24-year-old bracket beat the model by 12.1 percent. In another study, Showalter looked at Utah, which had been expanding vote-at-home county by county since 2012. This created a natural experiment. Showalter isolated voters clustered on either side of county lines and compared turnout changes between the ones who had vote-at-home and the ones who didn’t. The result: Traditional counties slightly underperformed the turnout model, while all-mail counties outperformed it by wide margins. The boosts were again more pronounced among young voters.

The direct partisan effects, however, were less clear. In Colorado, registered Republicans saw a slightly bigger boost than registered Democrats; in Utah, it was the reverse. In both states, independent voters, a huge bloc, also surged, making it impossible to know for sure which party benefited. Still, the results were suggestive, since the biggest gains were among young people, who overwhelmingly lean liberal. It made a lot of sense to expect vote-by-mail to help Democrats.

But wait—not so fast. Two weeks ago, a group of Stanford researchers published a working paper that sought to isolate the impact of vote-at-home on partisan outcomes. The title makes their conclusion very clear: “The Neutral Partisan Effects of Vote-by-Mail: Evidence From County-Level Roll-Outs.” The researchers compared the shift over time in votes cast for Democrats between counties that had and hadn’t made the shift—so-called “difference in difference” analysis. At first they found a pretty big result: a 2.7 percent boost in votes for Democrats. But they still had to control for other factors that could be driving the difference—maybe blue counties were generally getting bluer and red counties redder, independent of voting methods. “Places that adopt the policy earlier were moving toward Democratic presidential, gubernatorial, and senatorial candidates in the years prior to adoption, and after adopting it continues on that normal trend exactly as you would expect,” said Daniel M. Thompson, one of the authors.

After they controlled for those trends, the Democratic advantage shrunk to either 0.9 or 1 percent—with a 0.4 or 0.5 percent confidence interval. That is indeed small—but is it really “neutral”? “We can’t rule out that there are some small effects,” said Thompson. “But given the level of uncertainty, we can’t even say that the effect is greater than zero with a high degree of confidence.”

Still, elections can turn on margins smaller than the effects reported in the paper. Donald P. Green, a political scientist at Columbia who reviewed the paper, said in an email that the evidence of neutrality is “rather ambiguous” given the modest pro-Democratic tilt amid high statistical uncertainty. “Republicans are understandably wary, and I'm not sure that their concerns would be assuaged by the reassurances about statistical and nonstatistical error,” he wrote.

On balance, while there’s no proof that vote-at-home has a huge benefit for either party, the idea that it helps Democrats more hasn’t been disproven. It’s certainly a stretch to call it a “false claim,” as the Times did, or “patently incorrect,” as The Washington Post put it. (Trump’s suggestion that vote-by-mail enables rampant fraud, however, is indeed unfounded.) What’s clear is that the research is still limited, and that what’s true in the handful of vote-by-mail states doesn’t necessarily predict what would happen elsewhere.

Absentee Voting Is a Different Story

But here’s the thing: None of the research on universal vote-by-mail can tell us what will happen in November. It will be hard for any state to transition to a full-blown vote-at-home system by then. It’s more a question of whether they can dramatically expand absentee voting. There’s a big difference between who votes when everyone is automatically mailed a ballot and who will take advantage of absentee voting if Covid-19 remains a threat in November.

Consider what just happened in the Wisconsin primary, when there was an important race for the state supreme court. Nearly two-thirds of votes were cast absentee—far more than in the past. According to a New York Times analysis, those mailed-in votes skewed heavily in favor of the liberal candidate. That could be because Democrats were more concerned about the threat of the coronavirus, as polling amply demonstrates, and were thus more afraid to vote in person. But then how do you explain Florida’s primary, where the political scientist Charles Stewart III found that Republican voters made up a bigger share of absentee votes?

According to Rachel Bitecofer, a political scientist and election forecaster at the Niskanen Center, a center-right think tank, the answer is that absentee voting benefits whichever party does the best job getting its voters to take advantage of it. In Florida’s primary, where there’s a long history of Republican absentee voting, it was the GOP. “The Republican Party in Florida first recognized, ‘If we were to send applications out to our voter file of people who we know are Republicans, we can boost turnout of Republicans,’” Bitecofer said. But Democrats are catching up; a Politico story this week quoted Republican operatives fretting that they were less prepared for absentee voting this fall. According to Bitecofer, that organizing edge explains what happened in Wisconsin. “In Wisconsin’s recent election, [Democrats] made absentee voting a focal point of their strategy,” she said.

So what does it all mean? Based on the existing research, Republican fears of all-mail elections aren’t totally unfounded. But the partisan effect of expanded absentee voting—in which people still have to apply for ballots—is much harder to predict. Whatever partisan bias might lurk within a heavily absentee election in November will likely be swamped by other factors anyway. In Wisconsin, for example, many experts suspect that the state GOP’s effort to restrict absentee voting, and the media attention it drew, made Democratic voters even more riled up than they already were. Wisconsin Republicans may have been better off organizing their own voters than trying to hamstring the other side.

In that sense, the current tussle over whether to expand mail-in voting is a microcosm of how voting rights themselves have become polarized along partisan lines. Many leaders in the Republican Party have more or less openly committed themselves to suppressing participation—through techniques like strict voter ID laws, voter purges, and polling place closures—on the theory that it will help them win elections. That’s bad for small-d democracy. In the context of a viral pandemic, it’s also dangerous—and it could backfire.

The only thing we really know about voting this year is that absentee ballots are going to increase dramatically. Maybe making that easier would benefit Democrats, who live in densely populated urban areas where viral transmission is more likely. Or maybe it would benefit Republicans, who are older in general and so have more to fear of getting infected. There’s no way to know—which makes treating the question as one of partisan advantage thoroughly insane. Instead of focusing on which party might gain an edge, legislators and election officials would do well to spend their energy on what’s safest for voters and poll workers. It’s better to be remembered for keeping citizens safe than for forcing voters to choose between their health and the right to vote. On that point, the math is simple.