Reason's Peter Suderman mostly agrees that there's been a broad flip-flop within the GOP on the individual mandate. But, he asks, "couldn’t you accuse Democrats of more or less the same thing when it comes to Medicare reform?"

Democrats and liberal policy wonks took a similar turn with Medicare premium support, now championed in broad form by both GOP presidential nominee Mitt Romney and the party’s leading policy entrepreneur, House Budget Committee Chairman Paul Ryan. The story is remarkably similar: The idea started out as a policy promoted by prominent liberal wonks, briefly gathered support from a handful of top-level policymakers near the end of the Clinton presidency, and is now deeply opposed by the majority of Democrats, who often refer to the idea as a plan to “end Medicare as we know it” — or occasionally just a way to “end Medicare,” period.

Premium support, which would pay a flat rate toward the purchase of a private insurance plan for each Medicare beneficiary, was first developed by Alain Enthoven, a Democratic adviser who had previously served as a health policy consultant to President Jimmy Carter,  in “The History of Principles of Managed Competition” in 1993. In 1995, Henry Aaron, a scholar at Brookings who served as a senior official in President Carter’s Department of Health, Education, and Welfare, gave the policy its name — premium support — and suggested that it represented a Medicare reform compromise, a “middle ground” that could retains Medicare’s strengths but address budgetary challenges. In 1999, the National Bipartisan Commission on the Future of Medicare, which was chaired by Democratic Senator John Breaux and included Democratic Sen. Bob Kerrey, met to develop a proposal to reform the seniors’ health entitlement. The first item in the final proposal put forth by Breaux and supported by Kerrey was “the design of a premium support system.”

There are a few problems with drawing an equivalence between "premium support" in Medicare and the individual mandate in health care. The first, and biggest, is simply who supported it.

Joshua Roberts/Bloomberg

As Suderman writes, premium support garnered the support of a few Democratic wonks, and then-Sens. Breaux and Kerrey. Of those Democratic wonks, some, like Alice Rivlin, continue to support a premium support system. Breaux and Kerrey, meanwhile, were Democrats known for their frequent heterodoxies. The reason the report from the National Bipartisan Commission on the Future of Medicare never went anywhere is that every other Democrat on the Commission voted against the recommendations, and the Clinton White House quickly released a statement opposing premium support. There were, in other words, exactly no leading Democrats who signed onto premium support, and more than a few moved immediately to crush it. Arguably the most significant elected Democrat to sign onto premium support is Sen. Ron Wyden, who crafted a plan with Paul Ryan earlier this year.

Compare that to the individual mandate. The mandate's first political appearance was in a brief from the conservative Heritage Foundation. It then appeared in legislation co-sponsored by 18 Senate Republicans, including Bob Dole, who was then the minority leader of the Senate. Over the next decade, an individual mandate was central to plans released by Newt Gingrich, who many considered among the Republican Party's most important policy thinkers, and Mitt Romney, who is now the Republican Party's nominee for president. It was also in the Wyden-Bennett plan, which was cosponsored by, among others, Lamar Alexander, a member of the Senate Republican leadership team, and Chuck Grassley, the ranking Republican on the Senate Finance Committee. As late as June 2009, Grassley was telling Fox News, "there is a bipartisan consensus to have individual mandates." To my knowledge, there are no senior Republicans who have maintained or announced their support for an individual mandate in the manner of Rivlin or Wyden.

Premium support, in other words, was once endorsed by a handful of Democratic wonks and heterodox senators, though it was, from the beginning, a policy that gained the vast bulk of its political support from elected Republicans. It never gained any serious traction within the Democratic Party. The individual mandate was a Republican idea that garnered support from a diverse array of Republican leaders and institutions over the course of almost 15 years. And unlike with Breaux and Kerrey, many of those Republican leaders and institutions -- like Gingrich and Romney and Grassley and Hatch and the Heritage Foundation -- are still around today.

That's not to say motivated reasoning doesn't happen on both sides. But premium support isn't a very good example of it. Rather, the clearest example of motivated reasoning among Democrats probably comes in the civil liberties sphere, where President Obama has laid claim to powers -- including the right to assassinate American citizens abroad -- that would have appalled Democrats in the Bush years, and that clearly violate arguments many Democrats made about the proper boundaries of executive authority.

Finally, on premium support, it's not clear to me that Democrats actually oppose it. Much of the opposition to Ryan's plans has focused on the rate of growth in his Medicare vouchers. The initial version of his budget, which set that rate of growth at inflation and shifted excess cost onto beneficiaries, was, in many quarters, criticized explicitly for not being premium support. But opposing Ryan's plan and opposing premium support are different things, and it seems to me that Democrats have left themselves room to compromise on the policy in the future -- and, as I've written previously, I think such a bargain is well within the realm of plausibility. Republicans, conversely, have united around an argument that the individual mandate is flatly unconstitutional, and thus can never be implemented on a federal level no matter the policy it's embedded in.