Mr. Sanford's Wild Ride | The Nation

In secular matters, Sanford also bucks Republican orthodoxy. He says he doesn't believe in pre-emptive war and advocates a "conservationist" environmental agenda. Earlier this year the Sierra Club applauded Sanford's "bold decision" to oppose a coal plant planned for the state's Pee Dee River area. And after Rush Limbaugh announced his hope that Obama would fail as president, Sanford said, "Anyone who wants [Obama] to fail is an idiot, because it means we're all in trouble."

It's the rare Republican official who stands up to Limbaugh, and Sanford must have known he'd have a much better shot at becoming president if the radio host's wishes came true. After the 2008 election, exit polls showed that three of five voters said the economy was their top concern, and that remains true today. President Obama will not likely see a primary challenge, which means he won't have to face the argument--advanced by Nobel Prize laureates Paul Krugman and Joseph Stiglitz, among others--that $787 billion does not go far enough toward righting the economy. The likely Republican attack will draw on Chicago School economics, calling for less government meddling in the markets.

Until the recent scandal, Sanford had positioned himself as the most credible Republican to make such an attack in 2012. "Sanford's onto something--he's part of a national shift that's taken me by surprise," Grover Norquist, founder of Americans for Tax Reform, told me several weeks ago. "It used to be taxes that upset people, but the tea parties, which occurred before any tax hikes, demonstrated that it's government spending itself that bothers Americans."

Some compared Sanford and his devoted following to the buzz surrounding Texas Congressman Ron Paul's 2008 bid for the Republican nomination. "There's some similarity there, though I think Paul has more exotic views," said Patrick Caddell, Jimmy Carter's pollster and a frequent Fox News guest.

Now, however, Sanford has become only the latest casualty in a dwindling list of 2012 Republican hopefuls. Another potential candidate, Nevada Senator John Ensign, resigned his Senate leadership position earlier in June, after acknowledging an extramarital affair. Two other prominent Republican governors who have refused portions of the stimulus, Louisiana's Bobby Jindal and Texas's Rick Perry, have also seen their presidential chances hurt by recent public appearances. Many Republicans were underwhelmed by Jindal's widely televised reply to the president's first address to Congress in February, and Perry's allusions to possible Texan secession at a tea party rally likely constitutes an insurmountable gaffe.

Whether or not he manages to serve out his term, Sanford is unlikely to hold another office. But perhaps he can take solace in the credo of the US Term Limits Foundation, which published his memoir in 2000: "Remember, every town councilman wants to be a congressman; every congressman wants to be a senator; and every senator wants to be president." It's an indictment of political ambition, and until very recently it applied even to Mark Sanford, the self-described "citizen legislator" and reluctant politician who has never lost an election.

Ultimately, it was Sanford's personal foibles, not his political ones, that prompted a search for empathy. As he choked back tears in front of the Statehouse rotunda, Sanford said he would spend the days ahead traveling the state, talking to South Carolinians and asking for forgiveness.

"Governor Mark Sanford, fully aware of the consequences of his failure, told the truth with apparent contrition...and contrition is a start," the Palmetto Family Council, a faith-based foundation devoted to "defending and strengthening South Carolina families," said in its sympathetic statement issued after news of the governor's affair broke.

"I doubt this holier-than-thou group would be so understanding if he was a Democrat," said Andy Brack. But Brack, a relentless Sanford critic, doesn't believe the governor should resign. "It's a personal matter, and we shouldn't take our eyes off what's really troubling this state--a horrible education system, record unemployment and a looming healthcare crisis."

In his time as governor, Sanford has done little to improve the situation. Even though he lost the stimulus battle, his obstinacy cost the state desperately needed jobs. Before the courts weighed in, school districts had already announced they were giving up on the funds, laying off teachers and increasing class sizes. "We've had to make hiring decisions for the next school year with the money in limbo," said state superintendent Jim Rex. Other state agencies faced the same dilemma.

Before he vetoed the stimulus money, Sanford received a letter from the state's second-most-powerful Republican, State Senator Glenn McConnell, imploring him to take the federal funds. "While the attacks you have launched may have been intended to build your national image as a reformer, in the final analysis, the work of a true reformer is measured not by words or TV ads or by press releases but by what he or she has been able to accomplish in the arena of public service or for the people he or she represents," McConnell wrote. The letter identifies the qualities missing from the governor's political DNA--an ability to lead, which often necessitates compromise, and any semblance of empathy for the less fortunate citizens he represents--that are incumbent upon all presidential aspirants to at least pretend to possess.