ABC News’ Rick Klein reports: Democrats today got their first piece of encouraging Senate news, with a decision by Rep. Mike Pence, R-Ind., to forego a campaign against Sen. Evan Bayh, D-Ind. In a letter to supporters, as first reported by RedState.com, Pence cites his position as chairman of the Senate Republican Conference, as well as the chance to win back the majority in the House, in his decision to stay in the House and seek reelection to his current seat. “I am staying for two reasons. 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 writes. National Republicans, including officials with the National Republican Senatorial Committee, were eager to see Pence take on Bayh, a centrist Democrat and former governor who cruised to a second Senate term in 2004 with 62 percent of the vote. Without Pence in the race, Bayh will remain heavily favored to win a third term this year. Another factor: Pence is mentioned as a possible presidential candidate in 2012, and a campaign for the Senate would have been, at best, a distraction to such an effort, and would have risked a politically debilitating loss.