Official announcement later today. This was rumored, and I guess who can blame him. But it seems like a tough blow to the pro-life movement above all, and of course to the Democrats.From The Fix:

Stupak confirmed his decision to the Associated Press and is expected to formalize it as a press conference at 12:30 pm in Marquette, Michigan.Sources familiar with Stupak's thinking describe him as burned out from the long fight over health care in which he emerged as the leading voice of pro-life Democrats wary about the possibility that the legislation would allow federal funds to be spent on abortions.Stupak eventually voted for the final bill after Obama signed an executive order re-affirming the idea that no funds from the legislation would go toward abortions. In the wake of that vote he was treated as a hero within the Democratic caucus but the reaction toward him from activists on the right and left was significantly more vitriolic. Former Charlevoix County Commissioner Connie Saltonstall has announced she will take on Stupak in the state's Aug. 3 primary.Stupak's seat, which takes in much of northern Michigan's Upper Peninsula, will be a major takeover target for Republicans. Obama carried with with 50 percent in 2008 but George W. Bush won the district in 2000 and 2004.