Former Massachusetts governor Mitt Romney is still grappling with health care as an issue in his 2012 campaign. REUTERS/Steve Marcus/Las Vegas Sun

Romney is widely praised — by people on both sides of the aisle — as resolute and knowledgeable, committed to solving a major problem in the state by using the best means (and minds) at his disposal to do so.

Romney’s handling of health care even won praise from the likes of conservative stalwart and South Carolina Sen. Jim DeMint, who described the plan as evidence of using “good conservative ideas” and “apply[ing] them to the need to have everyone insured.”

DeMint made that comment in 2007. In the intervening four years, the political calculus around health care changed dramatically. And that’s Romney’s problem heading into 2012.

As the New Yorker’s Ryan Lizza (the second best journalist in DC with the word “lizza” in his last name) and the Globe’s Brian Mooney both detail, the ideas in Romney’s plan — particularly for the mandate requiring people to purchase health insurance — were developed in conservative think tanks like the Heritage Foundation in the 1990s.

While Romney understood that the idea of mandating coverage carried political risks, as it could be portrayed as an encroachment of the federal government into peoples’ lives, he ultimately supported the idea because he believed it was a living, breathing example of another pillar of the GOP platform: personal responsibility.

Unfortunately for Romney, in the battle of GOP ideas between personal responsibility and government creep, the latter won out — big time.

That victory, which Lizza attributes to the economic recession, the Obama Administration’s decision to push an economic stimulus package, bail out the auto industry and the financial sector and pass a health care bill, turned health care from Romney’s greatest strength to his biggest weakness — all without him changing a single thing about the Massachusetts plan.

This is, of course, not the first time in modern political history that a perceived strength transformed into a major weakness for a frontrunning candidate.

Think back to 2002 when Sen. Hillary Rodham Clinton along with most other Democrats with an eye on national bids down the line voted in favor of the use of force resolution against Iraq.

At the time, conventional wisdom held that any Democrat who wanted to challenge for the presidency had to show strong support for the war or run the risk of being labeled insufficiently tough in foreign affairs.

The intervening six years, however, changed the political calculus of the issue 180 degrees as the war effort bogged down and the search for weapons of mass destruction proved fruitless. Then-Illinois Sen. Barack Obama used his opposition to the war as his way into the race. Without that foothold, it’s hard to imagine Obama finding the space he needed to beat Clinton.

The change in Republican attitudes about health care is as stark as the transformation among Democrats about the war in Iraq.

In recent polling done by the Kaiser Family Foundation, just 17 percent of self-described Republicans said they felt favorably about President Obama’s health care plan, while 74 percent felt unfavorably including 53 percent who said they saw the law in a strongly unfavorable light.

Given those numbers, it’s not surprising that Romney is doing everything he can to highlight the differences between what he did in Massachusetts and what Obama did at the national level rather than talking about his own plan.

At the same time, polling from Suffolk University shows that Romney’s foray into health care reform is not much of an issue, at least when it comes to New Hampshire primary voters. More than half — 53 percent — said it had no effect on their vote.

In an interview with NBC’s Jamie Gangel that aired Tuesday morning, Romney noted that his legislation was just 70 pages long while the national law was 2,700 pages in length; “He is doing a lot of stuff that is just devastating to the health care system in this country,” Romney said of Obama. “He’s wrong.”

Focusing solely on Obama’s health care plan may the soundest strategy for Romney given the composition — or expected composition — of the Republican primary electorate in 2012.

But, his health care hurdle is evidence of the ever-changing nature of political campaigns — what’s viewed as good policy (and politics) one day won’t always be seen that way.

That also may provide some solace for Romney, however. While health care is being cast as the central issue for many Republican voters in 2012, who’s to say whether Republicans in Iowa or New Hampshire will still feel so strongly next February?