Rick Santorum’s front-runner status in the GOP presidential race is predicated on the idea that he is the consistent conservative alternative in the field.

And that image had some serious holes poked in it at Wednesday’s debate in Arizona.

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Mitt Romney and Ron Paul tag-teamed the former Pennsylvania senator much of the night, calling into question his conservatism on issues ranging from earmarks and fiscal policy to his endorsements and even what is often considered Santorum’s most solidly conservative credential — social issues.

Santorum hit back at Romney for hypocrisy on issues like government bailouts and earmarks. But in a night where charges were flying, the majority of them and the most novel ones were flying in Santorum’s direction.

Romney was fortunate to have an ally from the outset in Paul, who at several points in the debate went after Santorum and largely continued a pattern of helping Romney.

To begin the debate, Paul defended his anti-Santorum ad when CNN moderator John King brought it up, repeating his claim that Santorum is “a fake.”

“I find it really fascinating that, when people are running for office, they’re really fiscally conservative,” Paul said. “When they’re in office, they do something different.”

Later in the debate, Paul doubled down, hitting Santorum hard for voting in favor of spending bills that included funding for Planned Parenthood.

“If you voted for Planned Parenthood like the senator has, you voted for birth control pills,” Paul said. “And you literally, because funds are fungible, you literally vote for abortions because Planned Parenthood gets the money.”

This attack seemed to get more traction than any other, and Santorum’s explanation that the Planned Parenthood funding was part of a larger bill that he had to vote up or down on drew some groans from the audience — twice.

But it wasn’t the only point in the debate where Santorum took a hit.

Romney landed a pretty strong attack on an oldie-but-goodie piece of opposition research: Santorum’s support in 2004 of his moderate Pennsylvania Senate colleague, Arlen Specter.

Specter faced a tough primary in 2004, and Santorum’s endorsement of him was pivotal. Five years later, Specter voted for President Obama’s health-care bill and switched parites, becoming a Democrat prior to an unsuccessful 2010 reelection campaign.

“If you had said no to Arlen Specter, we would not have Obamacare,” Romney said.

Santorum was again put in the position of defending himself.

At various points in the debate, Santorum also made pains to justify the earmarking process in Congress and admitted a mistake voting for the “No Child Left Behind” education program.

Tthrough all of the attacks, Santorum threw some less-than-inspiring counterpunches. He seemed to want to debate the details of the legislative process and the merits of what Specter wound up doing — shepherding Republican-appointed Supreme Court nominees through the confirmation process as Senate Judiciary Committee chairman — rather than pointing out that Romney, for example, voted for Democratic Sen. Paul Tsongas in the 1992 presidential primary.

“I did the right thing for our country,” Santorum said of his Specter endorsement.

That may be a fair argument, but the name of the game for Santorum’s opponents was to simply cast doubt that Santorum is an across-the-board conservative.

And on that count, they — and specifically Romney — succeeded on Wednesday.