Nervous Democrats have already begun to blame one another for putting at risk "Ted Kennedy's seat"

As voters head to the polls in Massachusetts, nervous Democrats have already begun to blame one another for putting at risk the Senate seat Ted Kennedy held for more than 40 years.

Many angry Democrats blame their candidate, state Attorney General Martha Coakley, for running a sluggish campaign that let Republican Scott Brown set the contours of the race.

Some Democratic strategists lay the fault at the feet of President Barack Obama, saying he should have done more to sell the party’s agenda.

And in private conversations, Hill sources say White House chief of staff Rahm Emanuel has blamed Coakley, the Democratic Senatorial Campaign Committee and Democratic pollster Celinda Lake for failing to see Brown’s surge in time to stop it.

“With the legislative and political stakes so high, it’s unbelievable that the Senate committee and White House let this race get so out of hand,” said one senior Washington Democrat. “There’s a lot of blame to go around. Martha Coakley is only one of the problems here.”

Coakley is at the center of the criticism. Democrats complain that her campaign was caught napping after last month’s primary — and that Brown was able to use the pause to shape the race.

“A malaise set in, and there was a failure to take advantage of the opportunity to define yourself the next day” after the primary, said longtime Rep. Richard Neal (D-Mass.). “You thank people for the primary and then begin to define the next six weeks.”

Added Neal: “Going dark was not a great idea.” (CONTINUES HERE)