THE woman in question became a lawyer after some years as a community organizer, married a corporate lawyer and is the mother of two little girls, ages 9 and 6. Herself the daughter of a white American mother and a black African father — in this race-conscious country, she is considered black — she served as a state legislator for eight years, and became an inspirational voice for national unity.

Be honest: Do you think this is the biography of someone who could be elected to the United States Senate? After less than one term there, do you believe she could be a viable candidate to head the most powerful nation on earth?

If you answered no to either question, you’re not alone. Gender is probably the most restricting force in American life, whether the question is who must be in the kitchen or who could be in the White House. This country is way down the list of countries electing women and, according to one study, it polarizes gender roles more than the average democracy.

That’s why the Iowa primary was following our historical pattern of making change. Black men were given the vote a half-century before women of any race were allowed to mark a ballot, and generally have ascended to positions of power, from the military to the boardroom, before any women (with the possible exception of obedient family members in the latter).

If the lawyer described above had been just as charismatic but named, say, Achola Obama instead of Barack Obama, her goose would have been cooked long ago. Indeed, neither she nor Hillary Clinton could have used Mr. Obama’s public style — or Bill Clinton’s either — without being considered too emotional by Washington pundits.

So why is the sex barrier not taken as seriously as the racial one? The reasons are as pervasive as the air we breathe: because sexism is still confused with nature as racism once was; because anything that affects males is seen as more serious than anything that affects “only” the female half of the human race; because children are still raised mostly by women (to put it mildly) so men especially tend to feel they are regressing to childhood when dealing with a powerful woman; because racism stereotyped black men as more “masculine” for so long that some white men find their presence to be masculinity-affirming (as long as there aren’t too many of them); and because there is still no “right” way to be a woman in public power without being considered a you-know-what.

I’m not advocating a competition for who has it toughest. The caste systems of sex and race are interdependent and can only be uprooted together. That’s why Senators Clinton and Obama have to be careful not to let a healthy debate turn into the kind of hostility that the news media love. Both will need a coalition of outsiders to win a general election. The abolition and suffrage movements progressed when united and were damaged by division; we should remember that.

I’m supporting Senator Clinton because like Senator Obama she has community organizing experience, but she also has more years in the Senate, an unprecedented eight years of on-the-job training in the White House, no masculinity to prove, the potential to tap a huge reservoir of this country’s talent by her example, and now even the courage to break the no-tears rule. I’m not opposing Mr. Obama; if he’s the nominee, I’ll volunteer. Indeed, if you look at votes during their two-year overlap in the Senate, they were the same more than 90 percent of the time. Besides, to clean up the mess left by President Bush, we may need two terms of President Clinton and two of President Obama.

But what worries me is that he is seen as unifying by his race while she is seen as divisive by her sex.

What worries me is that she is accused of “playing the gender card” when citing the old boys’ club, while he is seen as unifying by citing civil rights confrontations.

What worries me is that male Iowa voters were seen as gender-free when supporting their own, while female voters were seen as biased if they did and disloyal if they didn’t.

What worries me is that reporters ignore Mr. Obama’s dependence on the old — for instance, the frequent campaign comparisons to John F. Kennedy — while not challenging the slander that her progressive policies are part of the Washington status quo.

What worries me is that some women, perhaps especially younger ones, hope to deny or escape the sexual caste system; thus Iowa women over 50 and 60, who disproportionately supported Senator Clinton, proved once again that women are the one group that grows more radical with age.

This country can no longer afford to choose our leaders from a talent pool limited by sex, race, money, powerful fathers and paper degrees. It’s time to take equal pride in breaking all the barriers. We have to be able to say: “I’m supporting her because she’ll be a great president and because she’s a woman.”