Updated: 1:11 p.m.House Republican Conference Chairman Mike Pence (Ind.) said Tuesday that he will not challenge Sen. Evan Bayh (D) this year.“After much prayer and deliberation, I have decided to remain in the House and to seek reelection to the 6th Congressional District in 2010,— Pence wrote in an “open letter to friends and supporters— that was posted on his Facebook page.“I am staying for two reasons,— Pence wrote. “First because I have been given the responsibility to shape the Republican comeback as a member of the House Republican Leadership and, second, because I believe Republicans will win back the majority in the House of Representatives in 2010.—Pence is forgoing a Senate race even though recent polling shows that he could have given Bayh a run for his money.Four Republicans are challenging Bayh including former Rep. John Hostettler and state Sen. Marlin Stutzman. The Senator is still heavily favored to win re-election at this point.Pence told conservative bloggers gathered at the Heritage Foundation on Tuesday that his decision to run for re-election was “easily the most difficult decision of my political career.—“I weighed the opportunity to serve in the Senate … versus what is a very real opportunity to take back the House of Representatives and make history,— he said, adding he felt it was his duty to remain in the House to help the GOP win back the majority. Pence said his decision did not mean Bayh was safe, and he encouraged other Republican candidates to come forward and challenge the Indiana Democrat. House Minority Leader John Boehner (R-Ohio) praised Pence’s decision to remain in the House. “Mike’s decision is good news for our conference and good news for the nation — and very bad news for the Democratic majority in the House of Representatives,— Boehner said in a statement. “It sends an unmistakable signal that Republicans are intent on doing everything possible this year to end the Democratic monopoly in Washington, build a lasting majority, and renew the drive for smaller, more accountable government.—