WASHINGTON  Senator Evan Bayh of Indiana announced on Monday that he would not seek re-election, sending a wave of distress over his fellow Democrats and focusing new attention on the view that unyielding partisanship had left Congress all but paralyzed.  Senator Evan Bayh, Democrat of Indiana, after a news conference in Indianapolis announcing he will not seek re-election.  The latest on President Obama, his administration and other news from Washington and around the nation. Join the discussion.  Mr. Bayh, a centrist and the son of a former senator, used the announcement that he would not seek a third term to lambaste a Senate that he described as frozen by partisan politics and incapable of passing even basic legislation.  “For some time, I have had a growing conviction that Congress is not operating as it should,” Mr. Bayh said. “There is too much partisanship and not enough progress  too much narrow ideology and not enough practical problem-solving. Even at a time of enormous challenge, the people’s business is not being done.”  Mr. Bayh’s decision staggered Democrats. It was the latest in a series of setbacks that illustrate just how far the party’s fortunes have fallen since President Obama came to office more than a year ago, sweeping big majorities into the House and Senate with him. Mr. Bayh stepped aside despite personal entreaties from Mr. Obama and his chief of staff, Rahm Emanuel, White House officials said.  Mr. Bayh was on the short list of candidates Mr. Obama considered for vice president before settling on Joseph R. Biden Jr. He was among the most prominent of moderate Democrats in Congress, but has been increasingly isolated over the past year as he has warned Democratic Congressional leaders that the push for big-ticket and expensive legislation was scaring off independent voters.  Although Indiana is considered a Republican-leaning state, Mr. Obama won it in 2008, and Mr. Bayh, 54, who served two terms as governor and won election to the Senate with more than 60 percent of the vote in each of his races, appeared to be in a good position to win a third term. His retirement greatly increases the chances of a Republican victory there, analysts from both parties said.  Even after the loss last month of the seat that had been held by Senator Edward M. Kennedy of Massachusetts, Democrats control the Senate by a margin of 59 to 41, leaving Republicans still facing long odds in their effort to win a majority. And Mr. Bayh, in an interview, argued that Democrats could hold on to his seat, noting that Republicans face a contested primary.  Still, Mr. Bayh’s exit darkens what already was a bleak election map for Senate Democrats. Because of retirements, Democrats face tough odds in retaining seats in Colorado, Delaware, Illinois, North Dakota and now Indiana. Democratic incumbents face tough going in Arkansas and Nevada. Republicans, though, have their own problems as they struggle to hold on to seats left open by retirements in Kentucky, Missouri, New Hampshire and Ohio.  What was most striking about Mr. Bayh’s announcement was the deep disillusionment he expressed with his place of employment, a feeling reflected in recent polls. In a New York Times/CBS News poll last week, 75 percent of respondents said they disapproved of the job Congress was doing; just 8 percent said members of Congress deserved re-election. Mr. Bayh pointed to the partisan standoff over efforts to create a commission to address the mounting national debt. Republicans blocked an effort pushed by Mr. Obama to create a bipartisan commission by legislation, with seven Republicans who had co-sponsored such an approach announcing they would vote against it.  In an interview, Mr. Bayh said he was startled at how much the Senate had changed since he arrived in 1998, and even more since his father, Birch Bayh, served in the Senate, from 1963 to 1981.  “This is colored by having observed the Senate in my father’s day,” Mr. Bayh said. “It wasn’t perfect; they had politics back then, too. But there was much more friendship across the aisles, and there was a greater willingness to put politics aside for the welfare of the country. I just don’t see that now.”  “In my father’s day, you legislated for four years and campaigned for two; now it’s full time. The politics never stops,” he said. “My bottom line is that there are a lot of really good people trapped in a dysfunctional system desperately in need of reform.”  Mr. Bayh was seen by fellow Democrats as someone who was not particularly happy with life in the Senate or very active there on a daily basis. He often popped in for votes and was quickly gone, and was known to make time for the school and sports events of his children. He only occasionally gave floor speeches.  Though Mr. Bayh had been considering his political future for some time, the timing of the announcement caught many top Democrats off guard. He did not inform Mr. Obama or other top party leaders of the timing of his decision, one associate said, so they would not make further efforts to talk him out of it; the office of Senator Harry Reid of Nevada, the Democratic leader, first learned of the decision from news accounts.  Until now, every indication was that Mr. Bayh was proceeding with the race this fall. He had collected the necessary petitions to be placed on the ballot and they were due to be filed at noon on Tuesday. Democrats had coordinated an extended campaign to release damaging political information about the Republican who had emerged as Mr. Bayh’s main threat, Daniel R. Coats, a former senator.  Mr. Bayh had already hired some campaign workers, and his campaign account had more than $13 million on hand.  Two Democratic House members from Indiana, Baron P. Hill and Brad Ellsworth, quickly emerged as likely candidates to fill the vacancy. A third possibility was Jonathan Weinzapfel, the mayor of Evansville, Democratic officials said  Democrats say that since no party candidate is likely to raise enough signatures to qualify for the ballot by the deadline on Friday, the state party will be allowed to select its Senate candidate. But Republicans are challenging that interpretation and said they were exploring their legal options to deny Democrats a candidate if no one meets the filing deadline.  On the Republican side, Mr. Coats faces a primary challenge from John Hostettler, a former member of Congress, and others. Representative Mike Pence, a conservative Republican who was the top choice of many Washington Republicans, announced earlier that he would not run and restated that intention on Monday.  Carl Hulse and Jeff Zeleny contributed reporting.
Senator Evan Bayh’s decision not to seek a third term gives Republicans a new chance to pick up a seat and Democrats fresh anxiety about losing the party’s center.