Both Barack Obama and Hillary Clinton would withdraw the United States from the North American free trade agreement within six months after becoming president, unless the agreement were completely renegotiated.
The Democratic candidates made the commitments yesterday at the final debate before next Tuesday's Texas and Ohio primaries.
Ms. Clinton said she would demand new environmental and labour provisions, and a new dispute-resolution mechanism, and would eliminate the right of outsiders to sue the United States for enacting measures to protect jobs.
To secure these and other concessions, Ms. Clinton said, under her presidency the United States would activate the clause that allows any country to withdraw from the deal with six months notice.
"I'm confident that as president, when I say we will opt out unless we renegotiate, that we will be able to renegotiate," she said when asked whether she was prepared to abandon NAFTA unless it were rewritten.
Mr. Obama agreed with Ms. Clinton's stand.
"I will make sure that we renegotiate in the same way that Senator Clinton talked about," he said. "I think, actually, Senator Clinton's answer on this one is right. I think we should use the hammer of a potential opt-out as leverage to ensure that we get labour and environmental standards that are enforced."
Both candidates have been critical of NAFTA throughout the nomination battle. This is the first time, however, they have said in a debate that they would activate the NAFTA clause that allows any of the three signatories - the United States, Canada and Mexico - to terminate the agreement with six months notice.
Political junkies waited, breath bated, to see if Ms. Clinton would take a roundhouse swing at Mr. Obama, in last night's debate.
Instead, the new underdog in the race for the Democratic presidential nomination jabbed and poked, claiming that some of his campaign literature was "very disturbing," and that, when reading his health-care platform "it's almost as though the health insurance companies and the Republicans wrote it."
Mr. Obama gravely disputed the accusation, and the whole debate quickly elevated into, yet again, a lengthy dispute over health-care policies.
If this is what one press report predicted would be the equivalent of Ms. Clinton throwing everything including "the kitchen sink" at Mr. Obama, in an effort to derail his growing popularity in Ohio and Texas, it must have come from a pretty small kitchen.
Last night's 20th Democratic presidential primary debate might have been the last. Unless Ms. Clinton is able to ring up convincing wins in both Ohio and Texas she will be under tremendous pressure to concede victory to Mr. Obama.
Those wins are becoming daily more problematic, with the polls narrowing in Ohio and Ms. Clinton essentially tied with Mr. Obama in Texas. Recent polls also have put Mr. Obama consistently ahead of Ms. Clinton nationally for the first time. A CBS News/New York Times survey has him at 54 per cent nationally, compared to 38 per cent for Ms. Clinton, a complete reversal of the leads that Ms. Clinton enjoyed going into the first caucuses and primaries in January. A USA Today poll had Mr. Obama ahead of Ms. Clinton 51 per cent to 39 per cent.
And in the latest unkind cut, Connecticut Senator Chris Dodd, who abandoned his own bid for the nomination after placing seventh in the Iowa caucuses, endorsed Mr. Obama yesterday.
At a press conference, Mr. Dodd said Mr. Obama "has been poked and prodded, analyzed and criticized, called too green, too trusting and for all of that has already won" a plethora of states and millions of votes, including 11 straight unanswered victories since Super Tuesday, Feb. 5.
"This is the moment for Democrats and independents and others to come together, to get behind this candidacy," Mr. Dodd said.
However, Ms. Clinton can't be entirely written off. She has been underestimated in the past, and she has come back to embarrass the pundits - in New Hampshire, and in the big Eastern states on the original Super Tuesday.
If she wins in Ohio and Texas, this entire narrative will need to be rewritten again.