I think the narrative changed for two reasons:

(1) People really expected IN to be taken by her with a fair bit to spare.  If, after three straight weeks of Scary Black Preacha(TM), she couldn't win very white, very blue-collar Indiana with a half-decent margin, it tells you the Pastorgate is worn out or close to it, and that Obama held up just fine.  It also tells you the "bitter" remarks and the "gas-tax holiday," at best for her, didn't mean a thing.  And, given that he improved substantially in those core demographics of hers, I think it tells you he probably won the argument on them.

Had Wright's video appeared before Obama's 11-contest streak, it might've made a difference.  But I think it's fair to say she lost this somewhere around Wisconsin.  In fact, I remember her "concession" speech that night from Texas, when she first came out to greet the crowd.  The look on her face struck me, and I thought, "She knows she lost it tonight, and she can't believe it."

(2) The math is now utterly crippling for her.  Even throwing in Florida and the Joseph Stalin Primary in Michigan, she still comes up short on delegates and the popular vote.  Unless he gets hit and killed by a bus, thus necessitating him dropping out, those metrics have now been decided.  She'll win West Virginia and Kentucky for an obvious reason.  He'll win Oregon, Montana and South Dakota.  She'll win Puerto Rico by a decent amount (probably about seven or eight points).  And we'll be right where we thought we'd be.

It's over.  It's just a question of whether or not she can accept it and move on.  I'd run out the rest of the primaries, or at least go to May 20th, if I were her.  It'd be the Mike Huckabee program.  No attacks, no big ad buys, etc.  Give the remaining folks a chance to make their voices heard by running out her remaining wins.  Have a little fun, and be done with it.

Conservatives want live babies so they can raise them to be dead soldiers. - George Carlin