There's a good reason for the otherwise inexplicable reality that in most surveys President Obama, despite his currently desiccated job approval ratings, leads all but one of his Republican rivals — and even against him, the president nonetheless runs neck and neck.

And there's a deeper reason, beyond the inchoate, predictable, and perennial yearning to find an alternative, why so many of the GOP's smartest strategists and most prodigious fund-raisers fought so hard to broaden their field of candidates. They sought someone else, anyone both serious and authentic  from Indiana's diminutive but economically literate Gov. Mitch Daniels, who once committed the conservative capital offense of contemplating a tax increase, to New Jersey's blunt, at times bullying, and comprehensively heavyweight Gov. Chris Christie, who believes in the heresy of global warming.  

What's unfolding in the Republican arena is not a campaign but a spectacle that repels mainstream voters and rejects or infects mainstream conservative candidates.

Those who looked elsewhere were implicitly confirming the judgment of the public at large. In the probable nadir of the Obama years, Americans feel overwhelmingly that the country is on the wrong track, but they think the GOP has the wrong candidates. In fact, there's hardly a plausible president in the current lineup, which is finally settled; in the resigned and now quieter recesses of Republican fear  they know they have to settle for what's there  that portends a clear and present danger of ultimate defeat.

What's unfolding in the Republican arena is not a campaign but a spectacle that repels mainstream voters and rejects or infects mainstream conservative candidates.

Thus Jon Huntsman, once an asteroid streaking into the GOP sky, has become an asterisk. And that's despite his intimidated assent to the absurd proposition that he, too, wouldn't countenance even $1 in new taxes for $9 in spending cuts. Huntsman, as Tish Durkin argued, has qualities that ought to recommend him — among them that, "He's not Romney... He's not crazy... He's not swearing on a stack of Bibles." Yet these very qualities are disqualifying in today's Republican Party. Huntsman doesn't want, or can't get, a séance with Donald Trump, who's become the grinning Joker of today's GOP. And Huntsman won't get a second look or a second chance  not this time around.

Instead the party marches to the tin drums of ideological extremism and angry fantasy, while its stiff and fragile frontrunner compliantly frog-marches to the right. Mitt Romney isn't setting the pace; he's trying to do just enough to placate a party where crazy now flourishes in many forms.

Last week's big event, blessedly for Rick Perry, was not a debate, but something called the Values Voter Summit  an inquisition on the religious Right where intolerance proved to be one of the highest values.

There, Rick Santorum, the former Pennsylvania senator resoundingly repudiated in his own state in 2006, denounced the president for not defending the Defense of Marriage Act — and then weirdly invited the audience to judge candidates by imagining "who they lay down with at night." According to the chairman of Mike Huckabee's upset win in Iowa four years ago, Santorum is the man who "has the chance to be the Huckabee" of 2012. That says it all about the delusional state of this season's Republican politics.

But there's more  endlessly more.

Newt Gingrich, who has climbed back to 10 percent in some national polls, agrees with Santorum in disdaining gay couples, although presumably Gingrich believes marriage is between one man and three women. He promised the so-called values voters that he would "ignore the Supreme Court on issues of national security" — just as he said FDR did during World War II when he ordered German saboteurs caught on American soil to be tried by a military tribunal. Gingrich, a self-fancied polymath, is more accurately a poly-mythologist: In this case, the Supreme Court upheld Roosevelt's decision in Ex parte Quirin. But Gingrich couldn't even bother to check Wikipedia, let alone the opinion itself.

Michele Bachmann can't be the nominee; but as the night closes in on her hubristic reach for the White House, her excesses and gaffes still deface the image of the GOP. She promised to abolish the Department of Education — a vow to values voters who apparently don't value education, at least the public kind. Two days earlier, typically tongue-tripping, she said on Fox News that she "want[ed] to see the tax cuts on job creators lowered." Huh?

The Tea Partiers have fled Bachmann, first for Rick Perry and then for former pizza magnate Herman Cain. (As my stepson Michael asked, have they ever actually tasted a Godfather's pizza?) Perry in turn proved wanting and waned in the polls  and Cain soon will. But they have both reinforced the notion of an out-of-touch, out-of-bounds Republican Party. Perry, who raised $17 million in just a few weeks  he has more money than verbs  has stumbled from savaging Social Security to salvaging a transparent cover story about the N-word name of his Texas hunting camp. Cain riled up the Values Voter Summit with his revelation that he had prayed his way to a presidential candidacy. I guess God is not only a Republican; this time, he's choosing Cain over the abler Romney.

So are a lot of Republicans  for the moment. It won't turn out that way. It's okay to applaud Cain, even to the rafters, but not to nominate him. Instead, we're witnessing a second gasp attempt to re-inflate Perry  whose fall should have been a windfall for Romney, but has given him only a small lead over Cain. For now, Romney just can't seem to get above 25 percent. Introducing and endorsing the Texas governor at the weekend's summit, the Rev. Robert Jeffress, the leader of the Southern Baptist Convention, hailed Perry as "a believer in Jesus Christ" — in contrast to Romney, a Mormon and therefore "a member of a cult."

There's persistent resistance to Romney  on the shameful ground of religious bigotry and on the defensible ground of doubts about his sincerity, his personality, and his principles. The result: The extremism and pratfalls of his opponents, which should benefit the Mitt-man by making him seem relatively sensible and reasonable, have generated a miasma that's enveloping the Romney campaign. Not only has he toed a bright right line on social issues; he's adopted the GOP habit of fact-free argument  almost certainly the easy reaction of someone who's already treated his public life as record-free.

So on the one hand, Romney charges Obama with slashing defense spending, when it has increased every year during this administration. On the other hand, he insists that he favored health-care reform only at the state level, when it's indisputable that he offered Massachusetts as a national model both in 2008 and in the first edition of his book. It was titled No Apologies, but he's been apologizing on health care ever since. And he never misses an opportunity for opportunism: An advocate of privatizing Social Security, he's now attacking Perry by posing as the program's defender.

Romney is a poser. But in the end, as I've written here before, he's also the one — because unless the GOP goes all in with the crazies, he's the only viable nominee the party now has. And once the theater of the primaries plays out as we should expect it to, we all know the game plan Romney will pursue  pivot to jobs and the economy. But here, too, he will be hobbled by his own record as a take-over artist who dismembered companies and destroyed jobs  and by the positions he's taken against tax fairness and in favor of unfettered speculation.

Even in an economy where the congressional GOP has intentionally and successfully stalled jobs and growth, the party's nominee may prove to be as vulnerable as the Christie-imploring Republicans calculated. It's clear that the president won't let 2012 be cast as a referendum; he's now setting out the basic choice: Who's on your side? Romney will call this class warfare, but people are coming to understand that we've already had a decade of class warfare  against the middle-class. That's what Occupy Wall Street is all about. And that's why Barack Obama should and will go the next step  and week after week, month after month, challenge Wall Street and vested interests across the board.

Mitt Romney will be ill-prepared for this contest. He will enter the general election burdened by the craziness to which he's had to kowtow. The primaries are also stripping away the strands of his already threadbare character. And they're leaving him on the wrong side of the great dividing line of 2012  for the privileged, not ordinary people.