The chairman of the Nevada Republican Party has been indicted. So has the former chairman of the Georgia G.O.P. In Michigan, a former co-chairwoman of the state party is facing charges.

As Donald J. Trump goes on trial in the New York criminal case, other investigations and prosecutions in five crucial swing states are continuing to scrutinize the steps that he and his allies took in trying to circumvent the will of voters after the 2020 election.

The investigations focus largely on the plan to deploy fake electors in states that Mr. Trump lost. Documents emerging from the state cases highlight divisions among Trump advisers after the 2020 election about whether to use hedging language in the phony certificates that they sent to Washington purporting to designate electoral votes for Mr. Trump. They also undercut claims by some Trump aides that they played little role in the fake-electors plan.

Georgia, Michigan and Nevada have already brought charges against a total of 25 fake electors, including current and former Republican Party leaders in those states. The Georgia case, led by Fani T. Willis, the district attorney of Fulton County, has gone further, bringing charges against Mr. Trump himself and a number of his advisers.

Investigations are also playing out in Wisconsin as well as in Arizona, where the state attorney general, Kris Mayes, is expected to bring charges soon. Grand jury subpoenas were recently issued to the people who acted as fake electors in Arizona, including Kelli Ward, a former state Republican chairwoman. Mike Roman, a former Trump campaign official who is already facing charges in Georgia, is also among those subpoenaed in the Arizona case.