PHILADELPHIA -- So much has changed since last they met -- but then again things look pretty much the same.
Nearly two months since the Democrats last debated -- and nearly 12 months since their first forum -- things have come full circle in a race where the frontrunners have flipped.
The pressure once again is on Sen. Barack Obama to exceed expectations Wednesday night at 8 pm ET at Philadelphia's National Constitution Center -- and Sen. Hillary Rodham Clinton is looking to close the deal in Pennsylvania, and look beyond.
Not that the stakes are the same; Obama's answers may be more closely watched than Clinton's, but there is only one delegate leader going into the debate, and there will only be one coming out of it.
The debate is Obama's best chance to take on questions over two controversies that have sidetracked his candidacy; his charge is to answer concerns about his views and his electability.
Clinton, D-N.Y., needs to demonstrate she's still in control of Pennsylvania -- her perilous path still intact despite distractions and obstacles of her own -- and sow the kind of serious doubts about Obama she needs to spring in the minds of superdelegates.
Yet the polls are looking more sweet than bitter for Obama, D-Ill.: The new ABC News/Washington Post national poll gives Obama an 11-point edge on the question of whom Democrats would like to see as the nominee -- and shows a spike in Clinton's negative perceptions.
"Barack Obama has knocked down one of the three tent poles of Hillary Clinton's campaign for president, surging ahead of her as the candidate Democrats see as most likely to win in November," ABC Polling Director Gary Langer writes.
"Democrats by a 2-1 margin, 62-31 percent, now see Obama as better able to win in November -- a dramatic turn from February, when Clinton held a scant 5-point edge on this measure, and more so from last fall, when she crushed her opponents on electability," Langer writes.
The battle "appears to have taken a toll on the image of Clinton, who was once seen as the favorite," Dan Balz and Jon Cohen write in The Washington Post. "In the new poll, 54 percent said they have an unfavorable view of Sen. Clinton, up from 40 percent a few days after she won the New Hampshire primary in early January. . . . In hypothetical general-election matchups, Obama holds a slim, five-point lead over McCain, while McCain is three points ahead of Clinton, which is within poll's margin of error."
She's got a narrow lead in Pennsylvania -- but that's about it. The Bloomberg/Los Angeles Times poll has Clinton up 46-41 in Pennsylvania, but down 40-35 in Indiana, and 47-34 in North Carolina.
"Barack Obama is leading Hillary Clinton in two of the next three Democratic primaries, an advantage, if it holds, that would allow him to sew up the nomination," Bloomberg's Heidi Przybyla writes.
"Hillary Rodham Clinton may not be headed toward the blockbuster victories she needs to jump-start her presidential bid -- even in Pennsylvania, the state that was supposed to be her ace in the hole," Janet Hook writes in the Los Angeles Times. "The survey found the New York senator leading Barack Obama by 5 percentage points in Pennsylvania, which votes next Tuesday. Such a margin would not give her much of a boost in the battle for the party's nomination."