When Rick Santorum’s nephew endorsed Ron Paul in an op-ed in The Daily Caller this week, he wrote: “If you want another big government politician who supports the status quo to run our country, you should vote for my uncle Rick Santorum.” Santorum respectfully and lovingly dismissed his young nephew’s endorsement. The senator said his nephew was just “going through a phase,” and later added: “I am a Reagan conservative. I am not a libertarian. And the people who are calling me a big government guy are libertarians.”

In an interview with Reason magazine in 1975, Ronald Reagan said:

If you analyze it I believe the very heart and soul of conservatism is libertarianism … The basis of conservatism is a desire for less government interference or less centralized authority or more individual freedom and this is a pretty general description also of what libertarianism is.

Says Santorum: “I fight very strongly against libertarian influence within the Republican Party and the conservative movement.”

Santorum is not a Reagan conservative. Not even close.

It surprises people when they learn I’m not a libertarian. As Ron Paul’s official campaign blogger, I’m often perceived as being a libertarian and I am no doubt sympathetic to many libertarian views. But ultimately I’m a traditional conservative — a limited-government constitutionalist of the Barry Goldwater variety. That said, I’m no more offended at being called a libertarian than a heavy metal fan is when called a rock and roller — both terms represent far more synthesis than antithesis. Santorum has no comprehension of this basic philosophical and historical truism.

Being against big government does not represent the totality of American conservatism, but it does represent what Reagan called the “heart and soul” of conservatism. Reagan recognized that the “desire for less government interference or less centralized authority or more individual freedom” was indeed libertarianism but that it was also conservatism. This observation was fairly commonplace on the right during Reagan’s time, when “conservatism” was still more of a substantive philosophy than a Republican marketing tool. For example, in his book “Flying High,” a memoir about the 1964 presidential campaign, William F. Buckley repeatedly refers to Goldwater’s philosophy as “libertarian” and his famous book “The Conscience of a Conservative” as a “libertarian tome.”

So, were Reagan and Buckley wrong about libertarianism’s kinship to conservatism — or is Santorum correct to treat libertarianism as something alien to conservatism? This depends on your definition of that term.

Let’s begin with Reagan’s definition. In addition to calling libertarianism the heart of conservatism, Reagan believed that the American right was a three-legged stool consisting of social conservatives, national security conservatives and economic/libertarian conservatives. Lose a leg and conservatism loses a lot, or so Reagan believed.

During the George W. Bush era, social and national security conservatives were represented well, while the economic/libertarian leg of the American right was virtually non-existent. Conservatives now look back and wonder how a Republican president could have spent so much money. They needn’t wonder long. The notion — which has been advanced by Santorum, Mike Huckabee and others — that libertarian influence in the Republican Party poses a problem is absurd. It was the lack of libertarian principles that defined Bush’s “deficits don’t matter” GOP. “Libertarian influence” in the Republican Party is a problem only if one thinks the national debt is not a problem. Before the tea party and Obama, few Republicans seemed to think it was.

And Santorum was their leader. Writes The Washington Examiner’s Timothy P. Carney:

As a member of Senate leadership, Santorum literally was an agent of the GOP establishment during passage of No Child Left Behind, the expansion of Medicare, and the overspending of the Bush era.

Red State’s Erick Erickson is even more explicit:

Rick Santorum is a pro-life statist. He is. You will have to deal with it. He is a big government conservative. Santorum is right on social issues, but has never let his love of social issues stand in the way of the creeping expansion of the welfare state. In fact, he has been complicit in the expansion of the welfare state.

Santorum not only rejects Reagan’s concept of conservatism as a three-legged stool, he admits he is eager to kick out the libertarian leg. When Santorum says, “I fight very strongly against libertarian influence within the Republican Party and the conservative movement,” he is essentially saying that he fights strongly against what Reagan considered the integral core of American conservatism. This is not to say that Reagan or even Goldwater were libertarianism personified — only that any person who calls themselves a “Goldwater” or “Reagan” conservative also must be a libertarian to some degree in their philosophy. Goldwater would have likely agreed with this sentiment. Reagan certainly did.

In a 2005 piece entitled “Goodbye to Goldwater,” Reason’s Jonathan Rauch explained how Santorum’s big government Republicanism is a rejection of traditional Goldwater/Reagan conservatism: “As Goldwater repudiated Dwight Eisenhower and Richard Nixon, so Santorum repudiates Goldwater and Ronald Reagan.”

Rauch continues:

Santorum shows no interest in defining principled limits on political power. His first priority is to make government pro-family, not to make it small. … The bold new challenge to the Goldwater-Reagan tradition in American politics comes not from the left but from the right.

When Reagan said “government is not the solution to our problem, government is the problem,” those 12 words defined traditional American conservatism as it has existed for most of its history. Santorum does not think government is a problem — he thinks people in the Republican Party who think government is the problem are a problem. The George W. Bush years represented a hard break from the Goldwater-Reagan tradition and Santorum arguably represented this rejection of Reagan conservatism better than any other Republican. He still does.

Santorum now says his nephew’s admiration for Ron Paul is a phase. Perhaps this is true. But rejecting Reagan conservatism was also a phase. The GOP of the last decade was emblematic of this disaster and Santorum was the constant pitchman for it. I’m not a libertarian, but like Reagan I understand well that we cannot have limited government without possessing the libertarian’s concern for individual liberty and fear of centralized power. Rick Santorum is adamantly not a libertarian — and in rejecting that philosophy wholesale, he continues to fight against what Ronald Reagan considered the heart and soul of the conservative movement.

Jack Hunter writes at the “Paulitical Ticker,” where he is the official Ron Paul 2012 campaign blogger.