HARRISBURG — Bill McSwain, the top federal prosecutor in Philadelphia under former President Donald Trump, will run for Pennsylvania governor, joining a crowded Republican field that may get bigger yet.

McSwain’s announcement — his first run for public office — was not a surprise.

He had written to Trump in July, seeking the former president’s endorsement for governor and, before that, had told party figures for months that he intended to run in next year’s election.

In a campaign video, McSwain took on Democratic Gov. Tom Wolf’s handling of the pandemic, saying “we will have no forced closings and no state dictates” and otherwise sounded familiar Republican notes on nationalized culture war issues, cutting taxes and “law and order.”

He leaned heavily on his background in law enforcement and service in the U.S. Marine Corps.

“I will fight with all the commitment I learned as a Marine and a prosecutor to restore law and order, freedom and economic opportunity,” he said.

McSwain, 52, lives in Chester County and went back to private law practice after more than three years as the U.S. attorney for the eastern district of Pennsylvania, which includes Philadelphia.