Five-Term Republican Sen. Susan Collins will learn who she will face in November as voters head to the polls in Maine's primary election on Tuesday.

Republican incumbents are facing tough challenges in Maine and Nevada. In South Carolina, a crowded field of MAGA-devoted Republicans are facing off to be the next governor.

Voters across Maine, Nevada, South Carolina and North Dakota head to the polls for another day of primary elections in America.

Voters are heading to the polls on June 9, 2026.