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.