It's official: Rep. Lou Barletta announced Tuesday his run in Pennsylvania's Senate race next year, joining a group of Republicans who want to unseat Democratic Sen. Bob Casey.

"I don't see running for the Senate to represent Pennsylvania as an opportunity," the Republican said in a campaign video. "I see it as a responsibility."

He included a barb against his Democratic opponent.

"Bob Casey is building up a war chest bankrolled by the most extreme liberal groups in the country," Barletta said. "Pennsylvania deserves better than an obstructionist senator."

The Pennsylvania Democratic Party called Barletta out following his announcement, attacking his vote in favor of repealing and replacing Obamacare.

“If Congressman Lou Barletta thinks voting to raise health care costs for seniors, gut protections for those with preexisting conditions, and send premiums skyrocketing will earn him a promotion, he’s in for a rude awakening," Pennsylvania Democratic Party spokesman Max Steele said in a statement. "Congressman Barletta is out of step with Pennsylvania values and in the pocket of D.C. Republicans and wealthy special interests."

Barletta is seeking to defeat Casey, who has represented Pennsylvania in the Senate since 2007, but he'll have to win a Republican primary first. Others who have announced their plans to run include state Reps. Jim Christiana and Rick Saccone, as well as Berwick borough councilman Andrew Shecktor.

Barletta so far is the only Republican candidate who has served in Congress. He's been in the House as Pennsylvania's 11th congressional district representative since 2011. His victory meant the defeat of an incumbent Democrat, Paul Kanjorski, who had held the seat for more than two decades.

Prior to serving in Congress, Barletta was the mayor of Hazleton, where he instituted policies to tamp down illegal immigration in the city.

He was an early supporter of Donald Trump during last year's presidential campaign, endorsing the then-candidate in March 2016.

“Donald Trump’s voice is resonating with average Americans who feel their voice has been lost by their party,” Barletta told The Washington Post at the time. “I believe this will become a new Republican Party, one that we should embrace.