Democratic and Republican sources say that Sen. Joe Lieberman, the independent Democrat from Connecticut and fierce supporter of the war in Iraq, will formally endorse Sen. John McCain tomorrow in New Hampshire.

A McCain spokesperson declined to comment.

A source familiar with the endorsement said that the two will appear of NBC’s Today Show tomorrow morning and at a town hall meeting in New Hampshire.

The endorsement could help McCain with independents in the state. Combine that with news that Rudy Giuliani is scaling back his advertising buy there [bold mine-DL], that the Boston Globe endorsed McCain, and that McCain’s rivals are spending most of their time in Iowa. ~Marc Ambinder

It’s not clear to me how this really helps very much with independents, and it could conceivably harm him.  New Hampshire voters have turned sharply against the GOP, in no small part because of the war, and independents in New Hampshire are unlikely to be receptive to the endorsement of a politician whose support for McCain is premised on McCain’s support for a war that aready hurts him with independents.  The important part of this story is that Giuliani is backing away from competing more actively in New Hampshire, where he had started trying to make a play for a decent finish.  As Huckabee has begun moving up more in N.H. and McCain maintaining a respectable second place, Giuliani was faced with the real danger of actively competing and still winding up in fourth (or worse, if Ron Paul has anything to say about it), so he has now retreated back to Florida where he vainly hopes to make his stand.   

P.S.  Here’s a classic Colbert moment from last year: “You cannot stop Joementum.”