Al Gore will endorse Howard Dean tomorrow.

Update: Joe Lieberman has issued this statement regarding Gore's upcoming Dean endorsement:

I was proud to have been chosen by Al Gore in 2000 to be a heartbeat away from the presidency -- and am determined to fight for what’s right, win this nomination, and defeat George W. Bush next year.

“I have a lot of respect for Al Gore -- that is why I kept my promise not to run if he did. Ultimately, the voters will make the determination and I will continue to make my case about taking our party and nation forward.”

Josh Marshall at Talking Points thinks Lieberman is slamming Gore with the "that's why I kept my promise" language. Atrios agrees.

We don't see it that way. We rank Lieberman at the bottom of our list of favored Democratic contenders, so our view is not an endorsement of him by any means, but we think it's a classy statement, free of criticism. He says he kept his promise because he respects Al Gore.

Maybe Lieberman is trying to say that his late entry into the race (out of deference to Al Gore's possible run) resulted in his campaign failing to take off. In which case, we think it's so subtle a criticism that the voters won't even pick up on it. We also think he'd be wrong to think that. Lieberman is the past. He wouldn't have made it no matter what.

Tim Russert thinks Al Gore is endorsing Dean in order to be in a position to run in 2008 if Dean loses. If he goes to bat for Dean and Dean loses, Russert says the Dems will owe him.

We do agree with just about everyone that Dean seems to have the nomination sewn up. As to whether he can beat Bush, we think he needs a very strong vice presidential candidate with a lot of foreign policy experience. And it's not Bob Graham.