COLUMBUS, Ohio — The Democratic presidential campaign hits a turning point Tuesday, when voters in Ohio and Texas either will put Hillary Clinton back into the race after a dismal month or drive her out.
Although some pundits already have written off Clinton, convincing wins in the two big states would give the New York senator a strong argument to keep campaigning after losing 11 straight contests, and could raise questions for the first time about rival Illinois Sen. Barack Obama's future.
A loss in one or both, though, after her campaign had called both states must-wins, would stoke enormous pressure on her to quit for the good of the party.
Even a split decision — such as winning Ohio and losing Texas — would leave her trailing Obama in delegates needed to secure the nomination, with little room left to catch up.
"She needs to score a knockout," said Paul Beck, a political scientist at the Ohio State University. "Marginal victories, for someone who was the front-runner, just don't do it. If she doesn't win both of them, and ekes out only a slender victory in one, she's got to seriously consider whether to go on."
In a sign of the kind of pressure that might come after Tuesday, New Mexico Gov. Bill Richardson, a party elder and former rival for the nomination, said this was the week to wrap up the increasingly testy nomination fight.
"D-Day is Tuesday. We have to have a positive campaign after Tuesday. Whoever has the most delegates after Tuesday, a clear lead, should be in my judgment the nominee," Richardson said Sunday on CBS.
Polls suggest that anything is possible Tuesday, with Clinton leading by an average of 4 percentage points in Ohio and the two locked in a dead heat in Texas. Two smaller states also vote Tuesday, with Rhode Island favoring Clinton and Vermont favoring Obama.
Mathematically, Tuesday's votes won't settle the nomination. Though Obama leads, he's still well short of the 2,025 delegates needed to assure a first-ballot nomination at the party's national convention.
But every victory puts him farther ahead in pledged delegates, and creates new pressure on free-agent "super" delegates to go with the popular-vote leader.
Even as they fought for votes, both campaigns jockeyed to cast Tuesday's results in favorable terms.
Clinton aides hedged their bets Monday and spun back their own spin, now saying she needs only "success" on Tuesday, not necessarily victories.
"Ultimately, we will be successful in these two states," said Mark Penn, Clinton's chief strategist. He declined to define success.
He and other Clinton aides credited her competitive standing to a tough new attack on Obama in a TV ad — and in Clinton's own stump rhetoric — that portrays him as too inexperienced to handle a crisis in the middle of the night.
"We've seen a tipping point and change in momentum. . . . It's tipping to Senator Clinton," Penn contended.
He declined to specify what experience Clinton has that equips her to handle a crisis at 3 in the morning, as her ad says.
Just weeks ago, Clinton's camp was far bolder about Ohio, where she had double-digit leads, and Texas, where she and her husband started building political relationships while working there for George McGovern's presidential campaign in 1972.
"If she wins Texas and Ohio, I think she will be the nominee. If you don't deliver for her, then I don't think she can be," Bill Clinton told Texas voters on Feb. 20.
"If she wins those, we then go on to April 22 in Pennsylvania," Clinton confidant Terry McAuliffe added on Feb. 26. "If we don't, then she has to make a decision on what she's going to do."
Obama aides noted that he leads among pledged delegates by 162 and that Clinton needs to win at least 62 percent of the delegates to be awarded after Tuesday to catch him, a very difficult task unless she starts winning states by landslide margins.
While Clinton still hopes to triumph by claiming the votes of "super delegates" — party officials and insiders who aren't chosen through primaries and caucuses — recent defections by some of them to Obama from Clinton suggest that it would take a run of primary wins to reverse the tide.