At the GOP debate last week in New Hampshire Mitt Romney issued a school-yard, bad-ass, you-want-some of-this challenge to President Obama.

“I can’t wait to debate President Obama on health care” he declared.

Then with a distinct cockiness, Gov. Romney added that he wants to ask the president: “Why didn’t you give me a call and ask what worked and what didn’t?”

That is pretty extraordinary given that President Obama’s Affordable Care Act (aka ObamaCare) operates on the very same principles as the plan that Romney put in place during his time as governor of Massachusetts. Not a single Republican voted to support the president’s national version of Romney’s Massachusetts plan. And Republican opposition to the Romney-like plan set a political fire to the Tea Party movement and led to the GOP gaining the majority of the House in the 2010 mid-terms.

All of that is enough to create surprise at hearing Romney boast to Republicans that he wants to engage the issue. But it is even more stunning for people who know Romney’s checkered history with political debates.

As the sportscaster Warner Wolf says – “Let’s Go to Videotape!”

The climax of Romney’s 1994 Senate campaign against the late Massachusetts Sen. Teddy Kennedy was a televised debate between the two candidates in Boston’s historic Faneuil Hall.

Heading into the debate, polls had Romney and Kennedy in a tight race and some political analysts said out loud Kennedy was in real danger of losing the Senate seat that he had held for three decades.

In the debate, Romney attacked Kennedy with charges that some of his family’s real estate holdings had benefited from government subsidies. Kennedy somberly replied: “Mr. Romney, my family did not enter public service for the money. And frankly, we’ve paid too high a price for it.”

Kennedy was of course referring to his two older brothers – President John F. Kennedy and Senator Bobby Kennedy – who were both assassinated.

Romney was caught flat-footed and he ultimately lost the election by 17 points.

And that was not the only moment when the debate went badly for Romney. As abortion was discussed, Romney professed to be pro-choice and at the same time pro-life in his personal beliefs. Sen. Kennedy walloped Romney by saying: “I am pro-choice. My opponent is multiple choice.”

Later, as governor of Massachusetts from 2003 to 2007, Romney tried to maintain a precarious balance between his personal pro-life beliefs and pro-choice policies in his administration.

That is, until he was running for the 2008 Republican nomination, when he stressed his pro-life credentials to anyone who would listen.

Political consultant Dick Morris termed his position a “flip-flop-flip” adding that in politics, “you only get to change your mind once on abortion.”

Also in that 1994 debate that Romney vowed he would do more to promote gay rights than Senator Kennedy. But later as governor, Romney was one of the earliest and most ardent opponents of same sex marriage.

Though Romney has undoubtedly grown and matured as a candidate since that debate performance, the lesson for his GOP rivals – and President Obama (if Romney wins the GOP nomination) -- is that debating does not appear to be one of the former governor’s strong points.

And that's why it was surprising that in last week’s Republican debate Romney’s challengers for the nomination treated him if they were in a boxing ring with the young Muhammad Ali.

Moderator John King gave former Minnesota Governor Tim Pawlenty a perfect opening to attack Romney on his Achilles heel – health care. Pawlenty did not take it. Instead, he reverted to Obama-bashing rather than criticizing Romney.

Pawlenty had previously described President Obama’s health care reform package as “Obamney-care” – referring to the similarities between Obama’s health law and the one enacted by governor.

Pawlenty later said he regretted not taking the opportunity to engage Romney.

President Obama is not likely to be so deferential. If the president ever does get the chance to debate Romney and Romney asks why he did not call him before passing the health care plan, Obama need only reply: “Because I wasn’t sure which Mitt Romney would answer the phone.”

And then President Obama may well be on his way to another Kennedy-style landslide victory.

Juan Williams is a writer, author and Fox News political analyst. His next book is "Muzzled: The Assault On Honest Debate" (Crown/Random House) which will be released in July.