Relax, everybody. Sarah Palin is never going to be president. The reason is both fundamental and obvious: She always takes the bait.

Recently confronted with the news that Levi Johnston, the 18-year-old father of her grandchild, had appeared on the Tyra Banks Show chatting about having had sex with Bristol Palin under the abstinence-advocating governor's roof, Palin basically had three options:

1. No comment on a private family matter.
2. “Of course I wish Levi hadn't done this, but he's still the father of my grandchild, and we all have to work together to bring up that beautiful baby.”
3. Publicly trash the little cad, magnifying the story and setting her family up for long-term conflict with Levi’s while—worst of all—making Palin seem much less eager to protect the baby than to whack his father.

Response No. 1 or No. 2 would have kept the story to a minimum and even flattered Palin through the contrast of her classy silence with Johnston's tacky spilling.

Characteristically, she went with No. 3. Game over.

Whatever Palin's defenders may cry, her troubles don’t stem from ideology, misogyny, or snobbery but from personality. To run for national office is to have shots fired constantly at oneself and one's family. To win is to master the art of whether, when, and how to fire back. If Palin can't restrain herself from attacking a teenager who is painfully well placed to attack her back, she is not getting anywhere near the White House. And while she needn't swear off exploiting her family—what politician would?—she does need to get a whole lot more subtle about it.

Palin is hardly the first politician to sell herself as a wonderful family person, and perhaps she is just that. But even more than for other public figures—including other female politicians—Palin’s family is a mixed political blessing. It is the key to her appeal but also a question mark.

This is not due to the headline-grabbing features of her household. It is because, so far, it is in the context of dealing with public revelations about her private life that Palin has expressed her most troubling personal quality—the almost Pavlovian inclination to react without thinking.

Looking back, it didn't bother me that she had a Down syndrome infant and a pregnant teenage daughter. It bothered me, a little, that she acquired both at about the same time and yet—by her own initial account, subsequently altered—she didn't think twice about adding a run for the vice presidency to her chores. (And yes, I would have had the same feeling about a similarly situated male candidate if he were running as the ultimate dad.)

Likewise, it didn't bother me that her daughter's pregnancy failed to reverse Palin's views on abstinence-only education; it bothered me that it seemed not to have occasioned the slightest flicker of doubt in her mind about those views. (Granted, when running for governor,  she did waffle on the abstinence-only question -- but that was politically expedient, not personally thoughtful.) Even now, it doesn't bother me that she wants to shred Levi Johnston for blabbing, which is an entirely normal impulse. But it bothers me a lot that she went ahead and did it—with maximum publicity.

After all, this young man will remain a powerful presence in the life of her daughter and grandson and she only recently portrayed him as her admirable, salt-of-the-earth, son-in-law-to-be. Politically, it couldn't matter less what kind of mother Palin truly is. But it couldn't matter more what kind of mother she seems to be. And increasingly, what she seems to be is craven.

No single such example should be a deal-breaker. And we can debate forever whether any such examples ought to count. But somewhere in that ill-defined yet decisive area of the gut where voters either warm up to or go cold on a candidate, they do count. And in aggregate, they're counting against her.

If this sounds like an attack on female ambition, it's not. On the contrary, I think all women, whatever their politics, should appreciate the way Palin wears her ambition—like a fabulous, flowing cape, not the usual hair shirt. At last, we have a wife-mother-politician—better yet, a right-wing Christian wife-mother-politician—who expresses not a drop of guilt about fitting herself into her own life. Whether by dint of her generation or her nature, Palin clearly feels no need to resort to the tiresome lament, previously required, about how dreadfully torn she feels because whenever she is at work she isn't at home and vice versa. Hallelujah! For that alone, women should cheer her hour upon the national stage.

Not that she's about to make an exit. At least through 2012, Palin will be a fact of political life. And if she stays true to form, she will greet each controversy, personal or political, with her trademark feistiness. Her supporters will love it. The media will love it. Most of all, her political opponents will love it. Because the more that Sarah Palin acts like a pistol, the less she looks less like a president.