Voters and election officials still do not know what rules may govern millions of mail ballots, as Trump asks the Supreme Court to revive curbs blocked by a federal judge and as states scramble to prepare for changes that could come after voting has begun.

As midterm elections approach in November, a legal battle is ensuing over attempts to regulate mail-in voting.

President Donald Trump’s administration asked the Supreme Court on Thursday to give the US Postal Service sweeping power to withhold delivery of mail ballots, setting up an…