Rep. Paul RyanPaul Davis RyanBiden's relationship with top House Republican is frosty The Hill's Morning Report - Presented by Emergent BioSolutions - Facebook upholds Trump ban; GOP leaders back Stefanik to replace Cheney Budowsky: Liz Cheney vs. conservatives in name only MORE (R-Wis.) won't run for Senate in 2012, he confirmed Tuesday.

Ryan, the chairman of the House Budget Committee, said he would prefer to stay in the House, where he enjoys a key perch of power at the center of Washington's prolonged fight over spending.

“I am grateful for the tremendous outpouring of encouragement that I have received from my friends and supporters since Senator Kohl announced he would not seek re-election to the U.S. Senate. For my family and me, the most important factor in making this decision was determining where I could make the biggest difference," he said in a statement.

If Ryan were to run statewide, the controversial 2012 budget he'd drafted as committee chairman would have almost certainly become the defining issue of the campaign. Democrats have used Ryan's budget, especially its proposed reforms to Medicare, as a political cudgel against Republicans. As it is, Democrats are likely to try to mount a strong challenge to Ryan in his relatively centrist House district.

Ryan teased his announcement earlier on CNBC, saying he would make his decision public after speaking with family, advisers and Wisconsin media. 


"I'm going to make an announcement later today," he said. 

Republicans are looking to flip the seat, which has been held by Sen. Herb Kohl (D-Wis.) for four terms. Kohl announced last week he is retiring at the end of this Congress.

After Ryan's decision, all eyes will be on former Wisconsin Gov. Tommy Thompson (R), another potential contender. He intends to seek the nomination only if Ryan decides not to run, a GOP official told The Hill Tuesday. 

Ryan provided few clues about his decision. But he did say his choice will depend on where he can have the biggest impact "trying to solve these budget and fiscal problems."

The list of Democrats considering a run for the vacant seat is said to include former Sen. Russ Feingold and Rep. Tammy BaldwinTammy Suzanne BaldwinSenate Democrats push Biden over raising refugee cap House Dems to unveil drug pricing measure ahead of Biden package World passes 3 million coronavirus deaths MORE, among others.

—This item was first posted at 8:28 a.m. and updated at 10:46 a.m.