Former Massachusetts Gov. Mitt Romney has renounced it. Former House Speaker Newt Gingrich says he doesn't believe in it anymore. Former Utah Gov. Jon Huntsman has brushed off suggestions he even considered it.
As the three have discovered, there is hardly a bigger black mark against a Republican presidential candidate today than the hint of past support for requiring Americans to get health insurance — as President Obama's new healthcare law mandates.
But Republicans were not always so hostile. Until the healthcare law passed last year, requiring medical insurance had a long history as a mainstream GOP idea.
It was promoted by conservative policy experts at places like the Heritage Foundation more than 20 years ago. In the 1990s, the concept was championed by Republicans on Capitol Hill.
And it was ultimately implemented by Romney in Massachusetts; in 2006 he became the first elected official from either party to sign a mandate into law.
"I still don't see what the objection is to the idea that people should not be allowed to run around without at least some basic health insurance," said Mark Pauly, a conservative health economist at the University of Pennsylvania's Wharton School.
Emphasizing personal responsibility, Pauly and other conservatives have argued that the uninsured incur medical bills as other Americans do; the tab is just picked up by someone else.
In 1991, Pauly wrote an influential plan for universal health coverage that relied on an insurance mandate to prevent people from "shifting costs to others." At the time, Washington was gearing up for a major debate over rising healthcare costs and covering the uninsured that would culminate in President Clinton's failed 1993 healthcare initiative.
Liberals, reluctant to leave the problem to the private sector, were pushing to create more government health insurance programs like Medicare or to require employers to offer health benefits.
"We were thinking, if you wanted to achieve universal coverage, what was the way to do it if you didn't do single payer?" said Paul Feldstein, a health economist at UC Irvine, who co-wrote the 1991 plan with Pauly.
Feldstein and Pauly compared mandatory health insurance to requirements to pay for Social Security, auto insurance or workers' compensation.
So too did the Heritage Foundation's Stuart Butler, who in 1989 wrote a health plan that also included an insurance requirement.
"If a young man wrecks his Porsche and has not had the foresight to obtain insurance, we may commiserate, but society feels no obligation to repair his car," Butler told a Tennessee health conference that year.
"But 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.… A mandate on individuals recognizes this implicit contract," said Butler, who was the foundation's director of domestic policy studies.
Even then, the mandate made some on the right uneasy.
A group of GOP lawmakers rebelled when leading Republican senators started working on healthcare legislation in the early '90s that included an insurance requirement.
Thomas Miller, a resident fellow at the conservative American Enterprise Institute, said many senior GOP lawmakers at that time were out of touch with the party base. "That is when RINOs ruled the Earth," he said, using the epithet that conservatives coined to deride party moderates as "Republicans in name only."
In 1993, however, more than a third of the Senate GOP caucus, including Minority Leader Bob Dole of Kansas, signed on to a proposal by Sen. John Chafee (D-R.I.) to expand health coverage using an insurance requirement.
The National Federation of Independent Business, a conservative small-business group, praised the bill "for its emphasis on individual responsibility." The group is now suing to block the mandate in the new healthcare law.
The 1993 GOP bill ultimately died quietly alongside the Clinton plan it was designed to head off.
But Republicans did not abandon the insurance mandate. A decade later, Romney made it a cornerstone of his plan to guarantee all Massachusetts residents health coverage, and was joined at the bill signing by the Heritage Foundation's Robert Moffit.
In 2007, Republicans once again began pushing a mandate at the federal level.
Ten Republican senators — including Tennessee's Lamar Alexander, now a GOP leader — signed on to a bill that year by Bennett and Sen. Ron Wyden (D-Ore.) to achieve universal health coverage by giving Americans tax credits to shop for coverage on their own. The bill would have penalized those who did not enroll.
Yet today, the insurance mandate remains the most unpopular part of the new healthcare law.
House Speaker John A. Boehner (R-Ohio), Senate Minority Leader Mitch McConnell (R-Ky.) and dozens of other GOP lawmakers have signed on to legal briefs supporting the multistate federal lawsuit by Republican governors challenging the constitutionality of the mandate.
"This law is an unprecedented expansion of federal power," Hatch said recently. "Our freedoms require limits on government."
Gingrich, who endorsed the idea of mandated coverage in his 2005 and 2008 books, last week told CBS News' "Face the Nation" that the requirement is "unconstitutional both on religious liberty and personal liberty grounds."
Huntsman, who has not officially entered the presidential race, did not include a mandate in the healthcare plan he signed into law in Utah in 2008.
There are sound policy reasons to oppose the specific mandate in the federal law, said Pauly at the University of Pennsylvania.
Many conservative health experts believe the Obama mandate will not be effective because it requires insurance that will be too costly and imposes too lax a penalty on those who remain uncovered.
But Gail Wilensky, who headed the Medicare and Medicaid programs under President George H.W. Bush, said technical reservations were not driving the Republican change of heart.
"This is clearly an emotional discussion about liberty and the aggressiveness of the federal government," Wilensky said.
Former Wyoming Sen. Alan Simpson, a conservative Republican who backed the Chafee bill in 2003, said many in his party seem to have adopted an approach that he described as, "Let's forget what we need to do and see if we can stick it to the Democrats … or stick it to the president."
"Nothing makes sense to me anymore," Simpson said.