Lyndon Johnson didn't get the Civil Rights Act through Congress by leaving it to them to display leadership, and signaling that no matter what passed, he would sign it.
Lyndon Johnson got the Civil Rights Act through Congress by walking up to wavering members of his party and putting them in a grip that congressmen and senators called "the full Johnson" (look it up). If he grabbed you in a full Johnson, it was his way of signaling you: "Cross me on this at your peril. Cross me on this and people in your district will suffer, and I will make sure that they know that it's because of you. Cross me on this and the volunteers at your headquarters will all go home. Cross me on this and the party will fund a challenger in your next primary. Cross me on this and nobody from your constituent service department will have their calls answered by any executive branch office. If knowing all of that, it's worth it to you to cross me on this, because you think the voters are that much on your side that they'll sacrifice every pork barrel project in their districts, every federal favor they need, and blame me rather than you for it? Well, that's your choice. But don't think for a second that I'm bluffing."
Franklin Roosevelt had Blue Dog Democrats in his Congress when he passed Social Security. Harry Truman had Blue Dog Democrats in his Congress when he passed Medicare. Lyndon Johnson had Blue Dog Democrats in his Congress when he passed the Civil Rights Act. Richard Nixon had Country Club Republicans in his Congress when he passed the Earned Income Tax Credit and the Environmental Protection Act. None of them got stabbed in the back by their own party members, let alone stabbed in the face the way Obama has been, because Roosevelt, Truman, Johnson, and Nixon knew something that Barack Obama doesn't seem to know. The President of the United States is the god-damned President of the United States, and the symbolic anointed and titular head of his political party, and neither of those are powerless positions from which you wheedle and beg as if you were negotiating from a position of weakness.
Sadly, no Democrat is afraid of Barack Obama.
I would start, frankly, with Joe Lieberman. He's the safest of safe targets, since he isn't even a Democrat any more. Now that he flatly can't be the 60th vote, he should kiss his beloved Homeland Security Committee chairmanship adios. Period. It's also long past time for the President to put the word down to the military academies, to the Social Security administration, and other executive branch offices that they shouldn't exactly rush to answer calls from Senator Lieberman's office. It's also long past time to find at least one of Senator Lieberman's beloved pet projects somewhere in Connecticut and declare it a waste of federal tax dollars, something that must be cut from the budget as a matter of principle, and send talking heads out to all the talk shows saying that it's time to get serious about cutting the budget, starting with this wasted spending in Connecticut. Never say why you're doing any of these things aloud, it doesn't need to be said. If asked, change the subject to some vaguely related subject that you'd rather talk about. You're the President of the United States, Mr. Obama. You can do that.
Make an example of two or three of the Blue Dogs, and the next time you sit down to negotiate, see if they don't negotiate in better faith, and if the next time they promise to vote for your bill if they get one concession, they keep their word this time instead of breaking their word and coming back for another bite of you.