It isn't every day that political candidates are asked whether the 10th Amendment allows states to nullify federal laws, but that was precisely the question Rick Santorum faced at a forum here a few days ago organized by a libertarian-leaning group.

To his credit, Santorum did not pander to the nullifier. "We had a Civil War about nullification," Santorum said with a smile. "I'm not sure I want to go there."

But Santorum's experience raises a larger question about this year's Republican primary contest: Rather than strengthening the party for the coming battle against President Obama, will it instead leave it more marginalized from the views of swing voters? Have the party's candidates, particularly Mitt Romney, had to spend too much time and energy wooing voters far to the right of the mainstream?

And something else happened during Sunday morning's debate on NBC's "Meet the Press": Front-runner Romney came under the first sustained attack from his opponents on his character, especially his core claim to be a citizen-businessman rather than a politician. The assaults were especially fierce from Santorum and Newt Gingrich.

A Rubicon was crossed when Gingrich looked at Romney at one point and commented acidly: "Can we drop a little bit of the pious baloney?" Both Santorum and Gingrich argued that Romney has been in and out of campaigns since 1994 and has fabricated a misleading public persona that tried to hide just how much of a politician he really is.

It was a telling charge that Obama would certainly highlight if Romney won the GOP nomination. Sunday's raucous encounter suggested that unless Romney closes the nomination struggle quickly, he could suffer further damage.

In the meantime, Jon Huntsman broke through in a way he hadn't before when he responded to Romney's criticism of the former Utah governor's service as Obama's ambassador to China. "This nation is divided because of attitudes like that," Huntsman said to applause.

Primary fights can splinter and dispirit a political party, an experience Democrats had over and over from the late 1960s into the early 1980s. But they can also mobilize and energize, exactly what happened during the Democrats' epic 2008 contest between Obama and Hillary Clinton. So far, the impact of this year's Republican contest has been more negative than positive. Most of the news from the race before the voting highlighted the shortcomings of the various contenders: Gingrich's jewelry-buying habits, Rick Perry's debate meltdowns, Herman Cain's personal troubles. This was happening as the party's image had already been dented by the unpopularity of the GOP in Congress.

There have been pluses for the Republicans. Many of the criticisms of Obama over the economy from the disciplined Romney could be persuasive later to moderates and independents. Santorum has reminded Republicans of the many working-class voters who have given the party victories in the past.

But the candidates have been pushed further to the anti-government right by Paul and further to the social-issue right by Santorum than will be convenient for the GOP come November.

There will be time for cleaning up from the primary fight. But Republicans have ceded Obama a head start -- just as the economic news has started to look up. And for a moment at least, Romney was shaken from his pedestal.