US Rep Mark Steven Kirk (R-IL) will run for US Senate, sources say

Rep. Mark Steven Kirk will run for the Senate next year, a Republican source confirmed Wednesday.

Kirk’s willingness to give up his House seat is a sign that the GOP will seriously compete in a Democratic-leaning state for the seat formerly held by President Obama.

Kirk made his decision after news reports that a potentially strong Democratic opponent, state Attorney General Lisa Madigan, has decided not run for the Senate.

The Senate seat now is held by appointed Sen. Roland W. Burris , a Democrat.

Now Mark Kirk wants to run for Senate.

The suburban Chicago Congressman had been thought of as the best chance for Republicans to win a U.S. Senate seat in Illinois, but wavered on whether he run.

Now that Lisa Madigan says she won't, a new report says Kirk will.

"CBS 2" in Chicago says it's talked with sources who know that Kirk is now getting into the race for what was Barack Obama's seat on Capitol Hill.

Two huge developments in one afternoon have shuffled Illinois’s political stage. First, Lisa Madigan announced that she would seek re-election rather than run for Governor or for Senate - a big surprise since the Attorney General would have been favored to win any seat on which she set her sights. Within hours, Politico and The Washington Post reported that Rep. Mark Kirk was telling Republican donors that he had decided to run for Senate.

This double shocker boosts the GOP’s prospects to capture Barack Obama’s former Senate seat, solidifies Pat Quinn’s hold on the governorship and sparks an open House race that should help cheer up concerned Democrats.