This is it, showdown at the Supreme Court corral—or Three Days That Could End America, as one conservative website put it.

At the heart of the apocalyptic rhetoric is the individual mandate—that not long ago was considered a conservative idea.

“Nobody was saying that it was creeping socialism or unconstitutional at the time. A lot of conservatives were for it,” former GOP senator Bob Bennett told me yesterday, looking back to the 1993 fight against “Hillarycare.”

The roadmap for what was then the signature Republican approach to health-care reform was provided by the once quintessentially Reaganaut think tank, the Heritage Foundation, which now denounces “the cancer of Obamacare.” The offending document was written in 1989, at the dawn of the first Bush presidency, and its rationale for the individual mandate was as follows:

“There is an implicit contract between households in society, based on the notion that health insurance is not like other forms of insurance protection. If a young man wrecks his Porsche and does not have the foresight to obtain insurance, we may commiserate but society feels no obligation to repair his car. Healthcare is different. If a man is struck down by a heart attack in the street, Americans will care for him whether or not he has insurance. If we find that he has spent his money on other things rather than insurance, we may be angry but we will not deny him services – even if that means more prudent citizens end up paying the tab … A mandate on individuals recognizes this implicit contract.”

This is, of course, almost precisely the argument made by both the Obama administration and Governor Romney when he was preparing his signature legislative accomplishment in Massachusetts. Namely, that we have a hole in the social contract, where a lack of individual responsibility causes great financial costs for society as a whole in the realm of health care, which everyone will need at some point in their lives. The solution, reiterated several times by Heritage in policy papers leading up to the fight over Hillarycare, was to put an end to fiscally irresponsible freeloaders by advancing the principle of individual responsibility. By comparison, the Clinton health plan’s imposition of a requirement for employers to provide health insurance purchased through HMOs seemed positively socialistic.

In another time, President Obama’s adoption of a Republican policy to pass health-care reform could have been characterized as classic Clintonian triangulation, an extension of the dynamic that enabled a Southern Democrat like Lyndon Johnson to pass civil-rights legislation or Nixon to go to China.

But in our polarized era, memory is short and policy consistency often takes a backseat to partisan expediency. “It is easier to get things done in Congress when people talk across the partisan divides rather than scream,” said Bennett, himself the victim of a Utah Tea Party purge in 2010. Among his chief sins was cosponsoring a bipartisan health-care-reform plan with Sen. Ron Wyden, a Democrat from Oregon. In their plan, the individual mandate—uncontroversial as recently as three years ago—was also front and center.

Bennett, who opposed “Obamacare” and before that “Hillarycare”, is in a unique position to weigh in on the conservative merits of the individual mandate, which was at the heart of three pieces of legislation he backed in his career. In addition to the Wyden-Bennett Act introduced in 2007 and 2009 that would have required all Americans, except those opposed on religious grounds, to purchase insurance, he backed two measures in 1993—the Consumer Choice Health Security Act and the Health Equity and Access Reform Today Act—that both involved an individual mandate.

“Back in ‘Hillarycare’ days, the argument was made that it was wrong for the government to require businesses to provide insurance to employees. That was the argument that was made and it reflected the reality of the U.S. marketplace,” says Bennett. “That was the way we defeated Hillarycare at the time.”

The Clintons’ effort to first craft health-care reform in private and then impose it on Congress was ultimately rejected, in part because of the lack of transparency of the process. But give Republicans credit for proposing an actionable alternative rooted in their traditional philosophic focus on individual responsibility.

Senator Bennett is quick to caution that he believes the Affordable Care Act signed into law by president Obama is “terrible policy,” and says he is proud to have voted against it. He also does not think that all Republican opposition to the mandate is entirely a case of situational ethics.

“I’m sure that there are some conservatives who didn’t really think it through and have come to conclude that it was a problematic idea,” says Bennett. “But there are others who are opposing it for Tea Party and partisan purposes—and they haven’t thought it through either.”

One notable beacon of philosophic consistency in this fear-mongering fray is the CATO Institute, which denounced the individual mandate as unconstitutional back in 1993 when it was a Republican-backed idea, saying “the mandate it imposes on all Americans undermines the traditional principles of personal liberty and individual responsibility that provide essential bulwarks against an all-intrusive government control of healthcare.”

But while some libertarians can claim philosophic consistency in their opposition, there is no question that the individual mandate was once considered a workable solution by conservatives back when the core debates in Congress were about different approaches to solving common problems.

Among the many ironies amid the ruins of that era is the current contortions of the Republican frontrunner. Because when Mitt Romney defended the individual mandate as “ultimate conservatism” back in 2007, he was actually telling the truth. What’s changed is the politics, not the policy or the principle.