Saying there's no love lost between him and Congress, Sen. Evan Bayh announced Monday that he will not seek re-election this November.
The Indiana Democrat, whose retirement came as a surprise to many in his state and on Capitol Hill, lamented that partisan gridlock has made his job less gratifying and suggested he could serve the people of his state better in the private sector or at a non-profit. Calling his decision a "very difficult, deeply personal" one, Bayh said he had no interest in running in November solely "for the sake of winning an election."
"I love working for the people of Indiana," he said. "But I do not love Congress."
Bayh's decision hands Republicans an opportunity for a pick-up in a year when Democrats are already defending several open Senate seats.
The two-term senator, known as a moderate Democrat, had attracted a GOP challenge in recent days from former Sen. Dan Coats. But Bayh said he was "confident" about his chances at re-election, and several Democratic sources said the decision appeared to be personal, not political.
"After all these years, my passion for service to our fellow citizens is undiminished, but my desire to do so by serving in Congress has waned," Bayh said Monday. "For some time, I've had a growing conviction that Congress is not operating as it should. There is much too much partisanship and not enough progress. ... Even at a time of enormous national challenge, the people's business is not getting done."
President Obama said in a written statement that Bayh has "fought tirelessly for Indiana's working families, reaching across the aisle on issues ranging from job creation and economic growth to fiscal responsibility and national security."
A senior Obama administration official said Bayh called Obama Monday morning to discuss the decision and indicated the senator had been considering retirement for awhile.
"The president has had several conversations with Senator Bayh about 2010. Bayh made his final decision this weekend, and it is personal, not at all political," the official said. "He is by nature a governor -- not a senator."
Bayh is a former Indiana governor and secretary of state. One senior Democratic source told Fox News that recent polling showed Bayh way ahead of Coats, and that the retirement must have been a personal decision. Bayh's staff said the latest polling showed Bayh ahead of Coats by 20 points.
One Democratic source said Bayh did not initially tell Senate Majority Leader Harry Reid about his decision Monday. Sources said he informed his staff Friday.
In his announcement, Bayh left open the door for what he would do next. He listed as possibilities starting a business, joining an "institution of higher learning" and leading a charitable organization.
Bayh was talked about as a possible running mate in 2008 for Obama before Joe Biden was tapped. It's unclear whether he's positioning himself for a future presidential run. Asked if he intends to seek political office down the road, he said, "I'm not gonna say never, but it's not a part of my thinking whatsoever right now."
The scramble for Bayh's seat has already begun.
Indiana Democratic Rep. Brad Ellsworth said in a written statement Monday that some "have already encouraged" him to run and that he will spend the next few days considering "where I can best serve our state."
Sources told Fox News that Indiana Rep. Baron Hill is another possible Democratic contender to vie for Bayh's vacant seat. Republican Rep. Mike Pence said Monday he will run for re-election, and not for Bayh's seat. Coats said he will "continue to run just as hard and take nothing for granted."
The timing of the expected Bayh announcement creates a dilemma for Democrats, though, since the deadline for candidates' petitions to be submitted is Tuesday. That means Bayh's name could still be on the ballot in May's Democratic primary -- Democrats will have another opportunity to pick a candidate through a separate nominating process. The Democratic Congressional Campaign Committee is considering whether it would be possible for a replacement to be named.
The decision comes after Sen. Chris Dodd, D-Conn., and Sen. Byron Dorgan, D-N.D., both announced their retirements in January. Democrats are trying to defend open seats in Delaware and Illinois as well.
Republican incumbents are abandoning seats in Florida, Kansas, Kentucky, Missouri, New Hampshire and Ohio. More Senate Democratic incumbents are considered vulnerable, however.
Signs of Bayh's discontent with the direction of the economy and with Washington could be seen in his votes over the past year.
He was one of only two Democrats two vote against the president's budget last year. Earlier this year, Bayh voted against his party when Reid tried to bring up a 10-year, $245 billion measure designed to stop massive cuts in federal reimbursements paid to Medicare doctors. And though he voted for the $787 billion stimulus bill, he was part of a group that axed $100 million from the original product produced by leadership -- what Bayh at the time called "silly stuff."
During healthcare negotiations, Bayh made it clear he did not trust that the bill would really hold down deficit spending. He worked with other conservative members to craft a package designed to rein in future costs. Bayh was also known to oppose the so-called "cap and trade" climate legislation proposed by the Obama administration.
Indiana Republican Party Chairman Murray Clark called the retirement a "game changer."
He told Fox News Radio the announcement comes as a surprise -- and said that while Democrats are "vulnerable," he considered Bayh to be "formidable" in November.
"Our field is pretty well established but theirs obviously has been thrown into disarray to say the least," Clark said.
Fox News' Major Garrett, Trish Turner and Chad Pergram contributed to this report.