State GOP leaders are expected to throw their support behind Garrity. Many of them are worried about a second run from state Sen. Doug Mastriano.

Republicans hope Ms. Garrity, the state treasurer, will give them a shot against Gov. Josh Shapiro. But he will be tough to beat, and the Republican field could still be complicated by Doug Mastriano.

Pennsylvania Treasurer Stacy Garrity will seek the Republican nomination to challenge Gov. Josh Shapiro's reelection bid in 2026.