Extensive WaPo report:

When the novel coronavirus pandemic collided with this year’s primaries, states across the country raced to temporarily adjust voting procedures to make it safer for people to cast their ballots.

But efforts to set rules for the general election are now locked in more intractable fights, fueled by deepening polarization around voting practices and a torrent of litigation aimed at shaping how ballots are cast and counted.

While the vast majority of voters were permitted to cast absentee ballots during the primaries, only about 10 states so far have announced that they will make voting by mail easier for November, raising fears that Election Day could be marked by long lines and unsafe conditions at polling locations if the health crisis persists.

With Republican governors under pressure from President Trump not to expand voting by mail and many legislatures adjourned for the year or deadlocked along party lines, changes in the coming months are likely to come through court decisions.