It has been Mitt Romney’s successful strategy to keep a low profile, emerging periodically for fluent debate performances, while the conservative meteors streak and fade. Every week that an untested rival surges, dominates the news and then stumbles, every week that marginal candidates retain loyal supporters and divide the opposition, is a good week at Romney’s Boston headquarters.

Yet it is possible to be a stealth front-runner for only so long. Romney has begun to attract the abuse appropriate to his status. Down, down, down have gone the pure, the cocky, the uncompromised. But some conservatives are not resigned.

Romney’s main political vulnerability is a serious one. Running for Massachusetts’ governor in 2002, he was a pro-choice, economically centrist, culturally liberal, business-oriented Republican. Running for president in 2008, he was a thoroughly pro-life, orthodox supply-side, culturally conservative, Fox News Republican. Romney’s shape-shifting 2008 campaign only reinforced the impression of a consultant-driven candidate.

But conservatives — unsurprised by human frailty — know that great republics are constructed out of flawed materials. Some of Romney’s transformation is explainable as the result of ideological regionalism. It would be a rare candidate who could run and win in Massachusetts with the same message offered to Republican caucus-goers in Iowa. The ideological gap between Beacon Hill and Osceola is among the widest in American politics, and making the stretch is difficult to accomplish in a dignified fashion. But the problem is not unique to Romney. Rick Perry won in Texas with an approach to immigration that is hard to translate in South Carolina. Ronald Reagan, as California’s governor, approved the liberalization of abortion and divorce laws. For a governor seeking the presidency, such tensions often arise.

Being an elected Republican from Massachusetts all but guarantees past political heterodoxy. But a hungry political party will tolerate some heterodoxy in the nomination of a strong candidate — if it is convinced that his or her values are sound. The alternative is to rule out large portions of the country in the production of Republican presidents — or to reward candidates who have no governing experience at all.

So are Romney’s current views his most authentic ones? On some issues — say, health care policy — it is difficult for an outsider to tell. In a different political environment, I suspect that Romney would be proud of his Massachusetts health reform instead of struggling to minimize it. But in the current presidential cycle, Romney has an advantage. The main issues of this campaign — economic growth and budget restraint — are in the sweet spot of his convictions. Romney speaks on these matters with ease, authority and evident sincerity. On the largest topics of the day, the charge of inauthenticity doesn’t stick.

Romney also has the potential to allay the fears of many social conservatives. A position change on abortion is always damaging — particularly a relatively recent one. But Romney has converted to a view that seems more consistent with his background. Is it really reasonable to assume that a former Mormon bishop, deep down, is a cultural liberal?

Even conservatives who buy none of these explanations may calculate that Romney is acceptable. Precisely because he has a history of ideological heresy, it would be difficult for him to abandon his current, more conservative iteration. He has committed himself on key conservative issues. Having flipped, he could not flop without risking a conservative revolt. As a result, conservatives would have considerable leverage over a Romney administration.

There is, however, a less-cynical conservative case for Romney. Opponents accuse him of political pragmatism — of which he is clearly guilty. But Romney might put his pragmatism to good use. His economic advisers are solidly conservative. Before the primary season is done, we are likely to see some serious entitlement and tax reform proposals. A leadership team of Romney, Speaker John Boehner and Majority Leader Mitch McConnell might be just what the moment requires: prudent adults who are conservative but not too far ahead of the public. They would stand a decent chance at doing what it takes to encourage job creation and avoid fiscal disaster.

Prudence and the avoidance of disaster are not the most inspiring political themes. But they could appeal to conservatives and to others — if Romney can make the positive case for pragmatism.