Trump and Biden could formally secure their parties’ nominations with Tuesday’s primaries.

There’s no doubt that President Biden and former President Donald J. Trump will be their respective parties’ nominees, and neither will face credible challengers, but Tuesday’s primaries could be the ones that make it official.

A strong performance today could officially give Mr. Trump a majority of delegates in the Republican National Convention, and Mr. Biden could do the same on the Democratic side.

Georgia, Hawaii, Mississippi and Washington state vote on the Republican side. Voting for Democrats are Georgia, Mississippi, Washington and the Northern Mariana Islands, and Democrats abroad will complete their weeklong trial.

Republicans in the Northern Mariana Islands will vote on Friday, followed by Republicans in Guam on Saturday.

Most states voting this week are holding presidential elections only, with primaries for Congress, governorships and other ballots scheduled for the spring or summer. Mississippi is an exception: the primaries in the Senate and House of Representatives will also be up for vote there on Tuesday.