Georgia’s primary election last week was hardly an exemplar of democratic efficiency. Equipment malfunctioned, backup ballots went missing, lines stretched interminably and many voters waited for hours to cast a ballot — sometimes in vain.

One reason for the chaos? Thanks to the COVID-19 pandemic, hundreds of poll workers didn’t turn up. That should serve as a warning for November’s presidential election: All states need to offer no-excuse mail voting this year, and Congress should help them do it.

Even before the coronavirus, the share of votes cast by mail had been increasing in recent years, reaching about one-quarter in 2018. The practice has long been helpful for those who can’t get to a polling place due to disability, work or other concerns. It may also have broader advantages. In Colorado, which instituted all-mail voting in 2013, researchers found that turnout has increased and that voters of color have benefited in particular.

Although mail voting isn’t without risks, these shouldn’t be overblown. Misconduct is one reasonable concern. Yet research suggests it’s extremely rare: Over the past two decades, with some 250 million votes cast by mail nationally, there have been only 143 confirmed cases of fraud. Nor does increased vote-by-mail appear to favor one political party over the other.

Moreover, with 2 million U.S. coronavirus infections and counting, the case for voting remotely is especially strong in 2020. While no one can predict how the pandemic will look by November, it’s reasonable to expect that many voters — especially older ones — will still want to isolate themselves and that state officials will still be discouraging large crowds. That makes mail-in voting desirable purely on public-health grounds.

Ideally, then, states should be sending ballots to all registered voters well ahead of Election Day. Yet obstacles remain. Several states still require a valid reason for voters to mail in ballots and haven’t made accommodations specific to the coronavirus.

That should change. Even areas that have made good-faith efforts this year have run into trouble. While Georgia tried to ensure that all registered voters could easily get absentee forms, for instance, many never received their ballots. A similar foul-up marred the primary in Washington, D.C.

FROM AN EDITORIAL ON BLOOMBERG OPINION