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As the coronavirus pandemic fanned across the country in the spring, Democrats looking ahead to the presidential election urged people to stay home in November—and vote by mail.

Minnesota’s secretary of state encouraged all eligible voters to cast their ballot by mail. Virginia Governor Ralph Northam told “every Virginian who can vote by mail to do so.” The instruction echoed from Pennsylvania to Nevada, where Governor Steve Sisolak said, “We prefer that people stay home, especially if you’re in a vulnerable situation.”

The message was heard, loud and clear. An August Wall Street Journal/NBC poll found that roughly half of Biden voters expect to cast their ballot by mail this fall, an unprecedented figure. And, you might ask, why not? Mail-in voting reliably expands the electorate, with minimal fraud, without forcing people to queue with strangers and chance transmitting a deadly virus.

But the past few months have complicated the idea that voting in person is risky—and that voting by mail is entirely risk-free.

Voting in person is probably not as dangerous as Democratic leaders initially feared. Since the Centers for Disease Control and Prevention urged Americans to wear masks in public, no major outbreaks have been traced to voting queues. Experts now say that voting with a mask on is no more dangerous than going to a grocery store with a mask on—something millions of American do every week. Evidence of the safety of in-person voting spans the world. South Korea, where public mask wearing is nearly universal, held a national parliamentary election in April with its highest turnout in three decades. No outbreaks there.

While in-person voting looks safer than expected, mail-in voting looks more dangerous—not because of fraud, but because of human error and partisan politics.

Mail-in votes require several steps, and different steps in different locations, including postmarking the ballots, signing in various places, and using the proper number of envelopes. For that reason, it can confuse first-time voters, and even experienced voters used to queuing at local high schools. Two studies of the 2018 midterm elections in Florida and Georgia found that young and minority voters are especially likely to have their mail ballots rejected. (Both of those voting groups skew Democratic.)

With millions of people voting by mail for the first time this year, experts expect more errors—and more rejected ballots. In the 2020 primaries, more than 550,000 mail-in and absentee ballots were disqualified, a much higher number than four years ago. The problem is especially severe in some swing states. More than 23,000 mailed ballots were rejected in the presidential primaries in Wisconsin—more than Donald Trump’s margin of victory in that state in 2016. Deep-blue districts have had the same problem: New York City alone threw out more than 84,000 ballots this primary season.

In November, states should be more prepared for the onslaught of mailed ballots than they were this spring. “We’ve remedied several of the problems we had earlier this year, including new rules to allow election clerks to avoid overwork in November, to avoid bookkeeping errors,” Jocelyn Benson, Michigan’s secretary of state, told me.

But even as voters and states are struggling to adhere to new rules, the GOP is fighting to limit the admissibility of mail votes. The Pennsylvania GOP has asked the U.S. Supreme Court to overturn state law and declare invalid any ballots that arrive after Election Day, even if they are postmarked before November 3. That state’s Supreme Court recently ruled to throw out “naked ballots”—mail votes that aren’t sealed within two different envelopes—which could invalidate hundreds of thousands more votes. According to The Philadelphia Inquirer, more than 6 percent of the ballots in Philadelphia’s 2019 municipal election were “naked” ballots. Disqualifying one in 16 votes in Pennsylvania would be a historic disenfranchisement in a crucial swing state.

There is no question which party would benefit from the mass disqualification of mail-in ballots. According to polls, Democrats are three to four times more likely to vote by mail than Republicans.

And so, up and down the Republican Party, in the White House and in the state houses, officials are signaling their eagerness to throw the election results to the courts in order to discount ballots received through the mail. “We have major issues in the country today … with all of the talk about universal, unsolicited mail-in balloting,” Vice President Mike Pence said. “There is a possibility that election issues may come before the Supreme Court.”

Online and at the White House, skepticism about voting by mail takes on a conspiratorial tone. Articles and posts about “voter fraud, mail-in voting, or vote-by-mail” have garnered nearly 100 million interactions on social media over the past three months—more than QAnon-related stories. Leading this nonsense circus is America’s first family. President Trump has declared that mail-in voting is rife with fraud. His son has gone so far as to claim that Democrats will “add millions of fraudulent ballots that can cancel your vote and overturn the election.”

As always, the Trumps’ attempts to sow chaos are not entirely grounded in fact. Oregon, the first state to adopt a universal vote-by-mail system, had 15 identifiable cases of voter fraud in 15 million ballots cast over 19 years. Colorado has uncovered 14 cases of fraud out of a similar total since 2013, during which time Utah has seen just one case of fraud in the past 970,000 ballots. Across several states, voter fraud from mail-in ballots appears to be, rather literally, a one-in-a-million occurrence. Perhaps that’s why the president’s voting-fraud task force was quietly disbanded, having found little to justify its purpose.

“Today, our biggest looming challenge is the growth of misinformation to get people to question the sanctity of the very reliable process we’ve built in Michigan,” Benson told me. “We’ve identified robocalls in Detroit intimidating voters and threatening them against voting by mail. We regard this misinformation about mail-in ballots as a kind of voter suppression.”

This is where I would love to offer a simple summary of the state of mail-in voting. But no appropriate summary is simple. Mail-in votes are more convenient, but more easily disqualified; they are more error-prone, but not statistically fraudulent; they are more likely to expand the electorate, but at the cost of increasing the total number of rejected ballots.

So what are we to make of all this?

“I am concerned, but not panicked,” Elaine Kamarck, an elections researcher at the Brookings Institution, told me. If a clear majority emerges for Trump or Biden in November, she said, the parties would likely accept the outcome quickly. “But a close election could be a mess,” she said. “Every detail will be scrutinized—the postmark on the ballot, the signature, the envelope, everything. If the election isn’t close, nothing matters. If it is close, everything matters.”

I can imagine two very distinct futures—for the country and for the reputation of mail-in voting.

In the first scenario, Biden wins the national vote by approximately seven points, his current average lead. A narrow win in Florida all but assures his Electoral College victory on Election Night. Over the next few weeks, it becomes clear that Biden benefited from a large expansion of the Democratic electorate through mailed ballots. Liberal pundits hail Democrats’ mail-voting advocacy, as Republican consultants, licking their wounds, vow to push harder for mail-in voting in future elections. Democrats win—and so does the future of voting by mail.

In the second scenario, Biden wins the popular vote by closer to four points. By the end of Election Night, swing states such as Pennsylvania and Wisconsin are too close to call. Trench warfare breaks out over the mail-in vote, and lawyers from both parties dig in to fight ballot by ballot. In the following weeks, conspiracy theories about fraudulent votes and counter-theories about voter suppression take over both parties’ social-media feeds. Republican lawyers invalidate tens of thousands of mail-in ballots because of minor violations, such as incorrect envelope usage and signature discrepancies. With those mostly Democratic ballots discarded, Trump wins a narrow election in the fog of litigation, making him the second consecutive Republican president to lose the popular vote yet win in the appellate system. Liberal pundits blame Democratic leaders for urging their voters to stay home and rely on a mail system with a higher disqualification rate. Millions take to the streets in outrage, confident that Republicans have effectively stolen the election. Our year of plague ends with a constitutional crisis.

Although the first possibility is more likely, both scenarios together capture the Democrats’ vote-by-mail conundrum. Democrats’ big edge in early voting and mail-in votes might be a salutary achievement. But in a close election, the combination of innocent mistakes by voters, mass litigation in close states, and conspiracy theories about mail-in voting could create the mother of all electoral headaches.

Which brings us back to you, the voter, and the science of the pandemic. The coronavirus does not seem to spread effectively among quiet, masked people in grocery lines, or voting lines. If you are committed to voting this November, but on the fence about how to do so, do it in person, vote early if you can, and bring a mask.

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