Hillary Rodham Clinton’s New Hampshire comeback was impressive. But I remain convinced that if Barack Obama can show he is tough enough and pragmatic enough to win the presidency and serve with distinction, it would be the best thing that could happen to America and the world.

The "if," of course, is a big one. New Hampshire showed that many Democrats see Clinton as a safer choice. This is understandable. Obama is relatively untested, making it especially hard to predict what he would do and how he would fare in the world’s most challenging job. The big questions, in my view, are these:

Does this 46-year-old first-term senator have the inner steel to vanquish the Clinton and Republican attack machines; to drive hard bargains with foreign leaders; and to hit foreign enemies and nuke-seeking jihadists with the right mix of diplomacy, threats, and force?

Would this passionate critic of the Iraq war pull out so fast as to plunge the place into bloody chaos that might be avoided by the policy that the originally pro-war Clinton or the still-hawkish John McCain would follow?

Would this strong liberal with a voting record somewhat to the left of Clinton’s be pragmatic enough for centrists like me? Would he resist pressure from his party’s ideologues and interest groups to push protectionism, isolationism, unduly statist remedies for our broken educational and health care systems, more laws enriching multimillionaire trial lawyers, and judicial nominees bent on governing from the bench?

Subject to the answers, here’s why Obama has more potential than any other candidate to be a transformative president.

His mind. In a welcome contrast with the current president, Obama has displayed both an exceptionally powerful intellect and extraordinary eloquence. He has done this in winning the presidency of the elite Harvard Law Review; in teaching law at the University of Chicago; in writing an impressive 1995 autobiography, Dreams From My Father; and on the campaign trail.

To be sure, Clinton and several other candidates boast strong intellects, too. And her mastery of the issues is especially impressive. But Obama also "radiates a sense of good judgment," in the words of former Bush White House official Peter Wehner. This admittedly subjective assessment — to be tested in the coming weeks and months — may distinguish Obama from (among others) the rigidly uncompromising first lady who tried and disastrously failed to ram down the throats of the American people a gigantic, Rube Goldberg-style health care overhaul designed in secret by a closed circle of left-leaning policy wonks.

His heart. Obama has demonstrated a commitment to dispossessed people from the time when he passed up a prestigious Supreme Court clerkship to become a community organizer for the poor in Chicago. His eschewing of the race card and refusal to resort to attack politics — even when his campaign seemed to be going nowhere last summer — also speak well of his character. And although all presidential candidates sometimes bend the truth, Obama seems refreshingly honest, especially about himself.

His temperament. Obama’s campaign-trail pledges about bringing America together and assertions that "we are not as divided as our politics suggest" gain credence from his history of building coalitions across party and racial lines. President Bush, who once spoke of being "a uniter, not a divider," has chosen time after time to deepen our divisions. Obama seems the best bet to heal them. He evinces more open-mindedness and interest in conciliation and compromise than any other candidate except perhaps McCain.

His race. At a time when America is still plagued by racial divisions and reviled abroad, especially in the Muslim world, Obama’s half-black complexion is a precious asset.

At home, electing an African-American who preaches education and opportunity rather than grievance and reparations would provide the best imaginable beacon of hope for black children who have been misled by bad leaders into thinking that America is still too racist to give them a chance at success. (See my February 3, 2007, column.)

Overseas, as Andrew Sullivan writes in The Atlantic, Obama’s "face [would be] the most effective rebranding of the United States since Reagan…. In one simple image, America’s soft power [would be] ratcheted up not a notch, but a logarithm.

A brown-skinned man whose father was an African, who grew up in Indonesia and Hawaii, who attended a majority-Muslim school as a boy [would be the] most effective weapon against the demonization of America that fuels Islamist ideology."

Obama’s opposition to the Iraq war from 2002 on would also be a bonus diplomatically: More than any other candidate, he could give us a fresh start with a billion or more Bush-haters and — if he chose — use military force judiciously in Iraq and elsewhere relatively free from cynicism about his motives.
Now for some doubts.

His defeatism, so far, on Iraq. Like the other Democratic candidates, Obama refused to concede during a January 5 debate the documented fact that the "surge" has produced major military (if not political) progress in Iraq. Do such comments suggest that he would "snatch defeat out of the jaws of victory in Iraq," as conservative hawk Bill Kristol warns? I am not sure that "victory" is a possibility or that bloody chaos is avoidable without an unacceptably large, long-term American presence. But I worry that Obama’s strong anti-war rhetoric might predispose him to order a withdrawal that is so precipitous as to pave the way for a bloodbath.

I also fear, on the other hand, that John McCain’s dogged determination to stay as long as it takes to stabilize Iraq may cost too much in American lives and treasure. We face complex, difficult choices that call for adjusting our policy as the facts on the ground change. Some tough-minded Democratic experts see Clinton as the best bet to strike the right balance. Perhaps. But if Obama’s judgment is as good as I think it is, he would be driven more by the evolving realities in Iraq than by his defeatist campaign rhetoric.

His liberal voting record. Obama opposed now-Chief Justice John Roberts and now-Justice Samuel Alito, two well-qualified conservatives who cannot reasonably be called extreme. He supported Senate Democrats’ virtually unprecedented filibusters of other well-qualified judicial nominees. His voting record is almost down-the-line liberal. Could such a man really find common ground with conservatives and govern from the center?

This is a serious concern. But just as Obama is too liberal for my taste, the Republican contenders are too conservative. Short of supporting an independent candidate, we centrists will face the usual choice between a Democrat to our left and a Republican to our right. And barring extreme positions, I put more stock in their qualities of mind, heart, and temperament than in which candidate’s ideology seems a notch or two closer to mine.

Obama’s positions do not seem extreme. Take health care. For all of the warnings that Democrats would bring socialized medicine, Republicans have gone some distance toward socializing it already, especially through Bush’s Medicare prescription drug plan. Government’s role will continue to grow — less under Obama’s plan than under Clinton’s — and how much it grows may depend more on Congress than on the president.

On education, no candidate in either party seems a good bet to push through the radical reforms necessary to fix the K-12 school system, which is utterly failing our poor children and leaving middle-class kids ill-prepared for global competition. Obama at least supports merit pay for teachers, a necessary — if far from sufficient — show of independence from the anti-reform teachers unions.

His vagueness. Critics complain that Obama has so far gotten away with voicing vague aspirations rather than offering a menu of specific policy goals. This is mostly true. But it does not bother me much.

It is simply smart politics for Obama to be vague until he is forced to be more specific by the narrowing of the Democratic field or by the general election campaign. More details than necessary at this stage would either offend the primary electorate or — by pandering to it — hurt Obama in the general election and narrow his options as president.

His inexperience. The biggest question is whether the relatively inexperienced Obama has the savvy and toughness to shoulder the staggering responsibilities of the presidency in such dangerous times. He has so far run a more impressive campaign than most thought possible, and the battles of the coming weeks will tell us more.

But at best, it must be conceded, he has less experience in high-stakes political combat than Sen. Clinton and less big-time government experience than just about any successful presidential candidate in our history, save one: a less-than-successful one-term congressman named Abraham Lincoln.