Republican Dino Rossi officially filed Thursday to challenge Sen. Patty Murray (D-Wash.) in the fall. He says he jumped into the race because "our country is in trouble."

"The stakes are too high to sit on the sidelines and watch as our country heads towards a breaking point, and that is why I’m running for the U.S. Senate," he said.

Rossi is the first choice of many national Republicans, but he'll face a tough primary challenge from Clint Didier. Didier, a former Washington Redskins tight end, has the support of the Tea Party and Sarah Palin. Tea Party candidates recently won Republican Senate primaries in Kentucky and Nevada over party-backed favorites.

Rossi waited until May to say he was going to run, and the delay annoyed several Republicans, who worried a late start would hurt them in the general election. After Rossi announced, two GOP candidates, Sean Salazar and state Sen. Don Benton, dropped out of the primary and endorsed him.

He gained national attention in 2004 when he lost his campaign for governor by 133 votes after three recounts to Democrat Christine Gregoire. He ran against Gregoire again in 2008 and lost.

The Senate primary is August 17.