The ballot drop box is the latest legal battleground ahead of the presidential election.
Democrats across the country are promoting these locked metal boxes for voters who don’t feel safe voting in person due to the pandemic, and don't want to entrust their ballots to the U.S. Postal Service.
But Republican President Donald Trump's re-election campaign is trying to stop their use, suing Pennsylvania to force the critical swing state to pull all drop boxes used in the June primary.
Republicans argue that these boxes could enable voting fraud.
Experts say such fraud is rare.
The campaign said it bolstered its lawsuit with evidence of fraud, but that evidence has not been shared.
Pennsylvania’s Democratic Governor Tom Wolf defended the use of ballot boxes, arguing they are legal and essential, particularly in the age of the coronavirus.
Others agree. In Connecticut, local officials are recommending that voters return their ballots via drop box rather than through mail, after reports arose that some ballots mailed a week before the state’s primary arrived too late to be counted.
Battleground states such as Michigan and Wisconsin are pushing ahead, adding more drop boxes this year.
Eight other states already have laws in place on ballot drop boxes.
An MIT study found that they are popular: more than half of all ballots cast in Washington, Oregon and Colorado in 2016 were returned to a drop box or election office.
Elsewhere, they’re being rolled back. Republican officials in Tennessee and Missouri are trying to restrict drop boxes, saying by law ballots must be returned by mail.
Some experts say up to half of all votes cast in 2020 could be absentee.