This is actually pretty extraordinary; Democrats going on the record with their fears that Obama will drag them all down to disaster.

The New York Times:

Elected officials and party leaders at all levels said their worries have intensified as the economy has displayed new signs of weakness. They said the likelihood of a highly competitive 2012 race is increasing as the Republican field, once dismissed by many Democrats as too inexperienced and conservative to pose a serious threat, has started narrowing to two leading candidates, Mitt Romney and Rick Perry, who have executive experience and messages built around job creation.

And in a campaign cycle in which Democrats had entertained hopes of reversing losses from last year's midterm elections, some in the party fear that Mr. Obama's troubles could reverberate down the ballot into Congressional, state and local races.

"In my district, the enthusiasm for him has mostly evaporated," said Representative Peter A. DeFazio, Democrat of Oregon. "There is tremendous discontent with his direction."

[...]

"The alarms have already gone off in the Democratic grass roots," said Robert Zimmerman, a member of the Democratic National Committee from New York, who hopes the president's jobs plan can be a turning point. "If the Obama administration hasn't heard them, they should check the wiring of their alarm system."

What these professionals are seeing is that GOP candidates are beginning to be viewed by voters as viable alternatives to Obama - despite efforts to paint them all as radical extremists. This is a very bad sign for Democrats this far out from election day. Unless Obama can make the race about the Republicans - rather than his own failures - he is dead in the water. There is no case to be made for the president; only one that demonizes his opponent and frightens the American people into voting for him again.

Don't expect a wholesale jumping ship of Democrats. But there won't be many Democrats running commercials showing them palling around with Obama, or even showing which party they belong to either.