Updated: Feb. 15, 5:48 p.m.
Sen. Evan Bayh (D-Ind.) made his decision to retire without consulting Democratic leaders in Washington, D.C., although he had previously alerted President Barack Obama and Senate Majority Leader Harry Reid (D-Nev.) that he was considering calling it quits.
Democratic sources say Bayh, a former two-term governor, never took to the Senate. The moderate was increasingly fed up with what he viewed as an overly partisan institution and was stung by criticism from the left-wing Internet blogs that he was not a real Democrat.
"He's never liked being in the Senate," one Democrat said Monday of Bayh, the son of former Sen. Birch Bayh (D-Ind.).
One Democratic source said Reid's decision last week to shelve a bipartisan jobs package negotiated between Senate Finance Chairman Max Baucus (D-Mont.) and ranking member Chuck Grassley (R-Iowa) played a role in Bayh's decision.
Reid decided to go with a narrower package because the Baucus-Grassley agreement was not strictly focused on job creation.
"It was yet an additional thing that made him realize he hates the Senate," said the source. Bayh's second term is set to conclude at the end of this year.
A senior Democratic Senate aide noted that Bayh was upset with partisanship in the Senate long before the fight over health care or the jobs package. This aide said Democratic leaders have spent the past year trying to convince Bayh to run for re-election.
A second senior aide suggested that the majority's leadership has been anticipating the possibility of Bayh's retirement, which is why the Democratic Senatorial Campaign Committee has worked diligently over the past few weeks to tar former Sen. Dan Coats (R-Ind.), who is running for his old seat.
"All the work that went into defining Coats these last couple weeks was intended as a down payment on keeping Indiana in the safe column," this aide said.
Late Monday, Reid issued a statement, which read: "Evan Bayh has been a strong voice for Indiana for many years and I thank him for his service. I respect his decision to step aside and look forward to continuing working with him to create jobs, strengthen the economy and keep our country safe throughout the remainder of his term. I am also confident that the efforts of Senator Bayh along with those of the DSCC will keep this seat in the Democratic Caucus."