Based on some media accounts this morning, the answer appears to be yes.
CNN notes that in winning two more contests last night, Barack Obama did so by successfully chipping away at Hillary Clinton's base of support.
The Baltimore Sun suggests that Obama appears to be a kind-of runaway train at this point, and the chances are dwindling for Clinton to stop him.
The New York Times offers similar analysis.
The AP says that Obama also used his victory speech last night to begin establishing the differences between Republican John McCain and him.
And, finally, the Los Angeles Times says that Clinton might be missing a critical point -- Democratic voters are NOT responding to her argument that she is the better candidate because she, and not Obama, would be ready to lead the country on day one.
Keep one thing in mind: Obama is rolling, no question about it, but his delegate lead is still less than 100. Now, I understand that because Democratic contests are not winner take all that it is more difficult more Clinton to make up that deficit, but if she wins the three major states coming up (Texas, Ohio and Pennsylvania) the race will substantially tighten and there will be another interesting question to consider: Why is SHE winning the BIG states, but not the smaller ones?
Again, if she wins the next big three, she will have won California, New York, New Jersey, Massachusetts, Ohio, Texas, Pennsylvania, Florida and Michigan (though the last two are a bit dubious this year). The power of those wins likely will resonate with the superdelegates.
Of course, if she fails to capture Texas, Ohio and Pennsylvania...then her campaign is effectively over.