EARLIER THIS WEEK, Herman Cain announced that he was "reassessing" his presidential campaign. For those who don't know, "reassessing" is campaign-speak for "I don't have a chance in hell of winning but I'm gonna hang on until I get a political job or a sweet TV contract."

Sadly, Herman Cain's political demise wasn't prompted by his most glaring deficiency: the fact that he is stupid.

As we've seen with George W. Bush and Dan Quayle, the GOP is perfectly comfortable supporting intellectual featherweights. In the case of Cain, his poll numbers didn't dip when he proudly declared his ignorance about foreign leaders. His base of support didn't budge an inch when he said, without irony, that the nation needed a "leader not a reader." There was barely a ripple among loyalists when he struggled to understand a boilerplate question about U.S. involvement in Libya.

Nope, it wasn't idiocy that killed Cain. It was the clown car filled with an endless string of sexual-harassment accusations, capped off by revelations of an alleged 13-year affair with a woman named Ginger White.

That was too much, even for a party that regards sexual harassment as nothing more than a liberal myth - along with global warming, police brutality and Bono.

As a result, Cain had to go.

Of course, Cain isn't the only one with an Achilles' heel. Each of the remaining contenders has a personal, political or circumstantial soft spot that compromises his chances of winning.

Newt Gingrich: Unlike Cain, Newt's string of moral indiscretions are considered old news. Instead, Newt's weak spot is the very thing that makes him appealing to many voters: his intelligence.

Even though he often arrives at the wrong conclusion, the former House speaker is an intellectual heavyweight who approaches issues with complexity and nuance. Unfortunately, this gift makes him susceptible to attacks from ideological purists who confuse complexity with heresy. Take, for example, Gingrich's statement that he supports a humane stance on immigration. What should have been an axiomatic statement for someone from the "party of the family" turned into a full-fledged controversy. Gingrich's stubborn refusal to turn complicated questions into sound-bite answers just may cause his demise.

Mitt Romney: The front-runner has two prominent weaknesses. First, as governor of Massachusetts Romney has accumulated a closet full of liberal skeletons. From health care to women's rights, Romney took positions that make him anathema to dyed-in-the-wool conservatives. While he's shown that he's fully willing and able to tell conservatives whatever they want to hear, Romney's history will still give pause to primary voters.

The other issue for Romney is his Mormon background. Tragically, many voters remain bigoted about Mormonism, viewing it as an anti-Christian cult. Although Romney has done his best to prove that his faith is mainstream, many evangelical Christians just aren't buying it. This may prove disastrous for him in the general election.

Jon Huntsman: Huntsman's biggest weakness is that he's not Mitt Romney. Despite being the best all-around option for the GOP, Huntsman is hurt because there's another Mormon with executive experience in the race. That Romney is better looking, has stronger national name recognition, more money and considerably better hair makes Huntsman nothing more than Ja Rule to Romney's Tupac.

Rick Perry: Three reasons: 1) he can't debate, 2) he hangs out in places called "N-----head ranch" and 3) ummmmm, I can't remember . . . . Cheap joke, I know. But no less accurate.

Daily News editor-at-large Marc Lamont Hill is an associate professor of education at Columbia University and host of "Our World With Black Enterprise," which airs at 6 a.m. Sundays on TV One. Contact him at MLH@marclamonthill.com.