Pennsylvania Sen. Bob Casey’s announcement Monday that he will seek reelection makes him the latest swing-state Democrat to run again in a year that the party will be relying on battle-tested incumbents. 

The Democrat’s decision to seek a fourth term was expected but still welcomed by his party, which will be almost entirely on defense in next year’s elections as they try to maintain a narrow Senate majority.

“I’m running for re-election because with so much on the line for Pennsylvania’s working families, I want to keep delivering results for Pennsylvania,” Casey said in a statement. “There’s still more work to cut through the gridlock, stand up to powerful corporate special interests, and make the lives of hardworking Pennsylvanians a little bit easier.”

His announcement comes before any major Republican candidates have entered the race. Businessman Dave McCormick, who narrowly lost a GOP Senate primary in the Keystone State to Mehmet Oz last year, is considering another run, as is state Sen. Doug Mastriano, who lost a gubernatorial bid last year. 

Democrats hope Casey will benefit from a competitive GOP primary that could drain his opponent’s resources before the general election and force candidates to the right. Mastriano last week said in a Facebook video that he would win the nomination if he ran because the party’s establishment couldn’t win without the base.

“We remember how you treated us last year. We’re not going to forget. We might not unite behind your candidate,” Mastriano said. 

National Republican Senatorial Committee Chair Steve Daines has criticized Mastriano, saying he proved last year that he couldn’t win a general election. Daines, R-Mont., has said that the NRSC will get involved in primaries this year, after several far-right candidates lost last November. Other Republicans have encouraged McCormick to run again.

Casey is not expected to face a major primary challenge. Last year, he came out in support of legislation that would codify abortion rights after the draft of a Supreme Court ruling overturning Roe v. Wade leaked weeks before the opinion was released. Previously, he had been one of the only Democrats not to support the legislation. 

At the end of last year, Casey had $3 million on hand. The first fundraising reports of 2023 are due to the Federal Election Commission by Saturday. 

Earlier this year, Casey underwent surgery for prostate cancer. In February, his office said he should not require further treatment.