In almost every instance in the ongoing struggle over voting rights, Democrats are trying to make it easier for Americans to cast ballots, and Republicans are trying to make it harder.

Much of the fight involves voting by mail, which many people would prefer to do this year to minimize their risk of contracting the coronavirus. Lawyers have already filed more than 300 lawsuits, across 44 states, over issues related to voting in the pandemic. The most important cases are in the battleground states on which the presidential election or Senate control could hinge.

Pennsylvania: The state’s highest court has ruled that election officials should count mailed ballots that arrive up to three days after Election Day. Pennsylvania Republicans are trying to get the Supreme Court to reverse the order, so that only ballots received by Election Day will count.

North Carolina: Republicans and the Trump campaign have asked the Supreme Court to block the state’s board of elections from extending the deadline to receive mail ballots. The board has said ballots can arrive until Nov. 12, as long as they were mailed by Election Day.

Wisconsin: The five Republican-appointed justices on the Supreme Court sided on Monday with Republican officials in Wisconsin, ruling that ballots must arrive by 8 p.m. on election night to count. (A lower-court ruling would have let state officials count any mailed ballots postmarked by Election Day and received up to six days later.) In response, the state’s Democratic Party is urging voters to return mail ballots to drop boxes or clerk’s offices, rather than mail them.

Editor's Note: the Supreme Court has declined to act on the PA and NC cases at this time.