Barack Obama’s campaign has kicked into gear with a two-pronged push-back in the wake of his 31-point loss to Hillary Clinton in West Virginia last night.

The first push-back actually came before the loss was in the books. The campaign dispensed a widely circulated memo yesterday in an effort to dispell “myths” with “facts.” Among the items discussed: Divisions in the Democratic Party and Obama’s weakness among swing voters, independents, white voters, women and working-class voters. (Gee, what gives them the idea that the party could possibly be divided?) Check out the memo at RealClearPolitics.com.

The next push-back came in the form of a drawlin’ former U.S. senator and presidential candidate. John Edwards endorsed Obama tonight at a rally in Grand Rapids, Mich.

I told you earlier that the timing and placement of the endorsement, which is being described by CNN’s Anderson Cooper as “the biggest of this election season,” is nothing short of curious to me. Edwards seems to be giving away all the leverage he has worked so hard to protect since dropping out of the race in late January.

Now having had four hours to digest the news, pundits are in near-agreement that the timing of the endorsement is meant to put an abrupt end to Clinton’s victory lap and bookend her positive news cycle short of the 24-hour mark.

My favorite pundit, Gloria Borger, said she spoke to someone who spoke to Edwards today, and Edwards pulled the trigger on the endorsement today because he didn’t like the headlines that were coming out of West Virginia: that Obama can’t win white working-class voters—Edwards voters.

Time’s Mark Halperin said it was clear that Obama had become the leader of the Democratic pack, but that Edwards’ endorsement can’t “paper over” Obama’s problems with working-class whites.

Joe Klein added that Obama’s people hope Edwards’ endorsement will encourage Clinton to “say goodbye pretty soon” so that Obama can have the month of June to retool himself and his campaign—a breather of sorts—as Bill Clinton did in 1992.

Edwards took great pains to compliment Hillary Clinton and the strides she has made in her campaign. Klein noted that Edwards actually said more nice things about Clinton than he did about Obama. But Edwards left no doubt as to his support: “The reason I am here tonight is because Democratic voters in America have made their choice, and so have I.”

One more thing: Edwards appeared on Larry King Live Monday night—fewer than 48 hours before his endorsement of Obama—and demurred when asked about his endorsement:

KING: Now we go to Philadelphia. Senator John Edwards, the former candidate for the Democratic presidential nomination, former U.S. senator from North Carolina. He was also John Kerry’s running mate in 2004. You have not endorsed, senator. Some might say as a major figure in the party at this point, don’t you have a responsibility to endorse?

JOHN EDWARDS (D), FORMER PRESIDENTIAL CANDIDATE: No. I think that what I have a responsibility to do is make sure that the Democrats’ message and our cause is heard and that we’re united in the fall. You know, myself, Al Gore, I think there are some others who haven’t spoken out yet about this nomination battle. I think we have two great candidates. I have such an extraordinarily high opinion of both of them. You watch sort of what’s happened in the past, I think that some of the endorsements as opposed to helping unite have contributed to the divide. And what I don’t want to do is contribute to the divide. I mean, we had a primary in North Carolina where I live. I live in Chapel Hill, North Carolina. I voted in that primary. So obviously, I made a choice in that vote. But at least for this moment, I think the reasonable thing for me to do is let voters make their decision.

It would be really great if someone—ANYONE—would ask Edwards when he decided to make this endorsement. Was it triggered by West Virginia? Was the decision already made, and was Edwards just waiting on Obama to make the call? This seems like a pretty obvious line of questioning, especially in light of Edwards’ comments Monday. But it has, so far, gone unexplored.

Later, King asked Edwards whether he would consider running for vice president again:

KING: Senator Edwards, would you run again for vice president if asked?

EDWARDS: No. I don’t have any interest in it, no intention to do it. The cause of my life, Larry, is to do something about poverty in this country, and I’m going to pour my heart and soul into that. I knew you were going to ask me about this. But you know, we’re here in Philadelphia to launch a campaign to cut poverty in half in the next 10 years. I’m committed to this cause. We have wonderful organizations who are working on this cause. And I just came, in fact, today—I mentioned this to you earlier. Just came today from being on the Gulf Coast with Habitat for Humanity and President Carter. Earlier today I was hammering nails and building houses on the Gulf Coast. So that’s what my life is about now.

Maybe. But that didn’t stop Matt Drudge from posting a picture of Obama and Edwards above the headline, “The Ticket?”

We shall see.

Read the full transcript from Edwards’ appearance on Larry King Live here.