Election Day in the U.S. is unfolding like no other, with nearly 100 million Americans having already cast their ballots. Voters took advantage of absentee balloting and early in-person voting amid a pandemic that has killed more than 230,000 Americans and worries about whether the Postal Service would deliver their ballot on time. President Donald Trump has been claiming without evidence that mail ballots will lead to widespread voter fraud and has threatened to file lawsuits to stop the counting of late-arriving ballots in some states. He has especially targeted the key battleground state of Pennsylvania for legal challenges.