At a moment when many on the left are desperately trying to conjure up enthusiasm for Hillary Clinton's bid to become the first woman president, others on the left want to turn the word "woman" into a term of exclusion and oppression.This is just one of the more amusing ironies on display as what passes for liberalism today eats itself.No doubt you've heard: Bruce Jenner has become Caitlyn Jenner. I can't muster much outrage about this. If someone born a man wants to live as a woman, or vice versa, they are free to do so as far as I'm concerned. What does bother me is the way everyone is expected to celebrate Jenner's decision and courage. Why can't I just not care? Or, maybe I just don't want to be part of a massive public relations effort tied to the rollout of yet another reality show?While conservatives had their own list of complaints about this national celebration, the more intriguing ones came from the left. For instance, many people criticized the Vanity Fair cover of Jenner as a pinup. "One step forward for Caitlyn Jenner, one step back for womankind," Eric Sasson complained in The New Republic. "As a media sensation, Jenner had many choices for how to reveal herself to us, so the fact that she chose a way that only reinforces how much our society objectifies women is a bit distressing," he explained.Dana Beyer of Gender Rights Maryland argued fairly persuasively that it would have been better for her cause if Jenner had dressed as a businesswoman instead of as a sex symbol.One problem with this argument, as many of the people making it recognize, is that Jenner's business is the reality show celebrity-buzz racket. "The Sports Illustrated Swimsuit Issue" surely objectifies women, but it wouldn't sell nearly as many copies if it was the "Sports Illustrated Sensible Pantsuit Issue."Moreover, there's something gloriously perverse in celebrating someone's courage to boldly smash sexual categories and then, in the same breath, castigating them for reinforcing gender stereotypes. If men are to be free to become women, surely they get to decide what kind of women they want to be. The first word in Vanity Fair is, after all, "Vanity." The Sports Illustrated swimsuit models seem very happy to be paid lots of money to be objectified by the male gaze. Who am I to judge?But the most fascinating argument comes from those who have no problem with Jenner changing genders, but have serious misgivings about the word "woman."On a recent MSNBC panel celebrating the "Jenner Effect," The Nation's Michelle Goldberg (no relation), noted that many young feminists "no longer want to use the word 'woman' in relation to abortion because it excludes trans men." There's a lot of "conceptual murk to clear away," she added with admirable understatement, "but among younger people that I've talked to, it almost seems amazing to them that anybody would question the need to have gender-neutral language."In a fascinating piece for the New Yorker, Goldberg wrote about this growing schism. Rachel Ivey, a young feminist told Goldberg, "If I were to say in a typical women's-studies class today, 'Female people are oppressed on the basis of reproduction,' I would get called out."Some students, she explained, would ask, "What about women who are male?"Next stop: the other side of the looking glass.On most days of the week, liberals are fond of claiming that Republicans are "anti-science" on everything from global warming to evolution. Well, last I checked, biology hadn't been declared a branch of the humanities.Bruce Jenner was 65 years old when he decided to be a she, but that's not why Caitlyn can't have a baby. Figuratively speaking, removing the spigot won't change the rest of the plumbing. That's not patriarchal oppression talking. That's science. And no matter how fluid gender may or may not be, the biological category of "female" isn't going away anytime soon.I have sympathy for people who are convinced they were born the wrong sex. But feeling oppressed by a category doesn't render that category illegitimate or unreal (short people may resent being short, but that doesn't nullify the concept of height).Nevertheless, I will certainly enjoy watching this argument unfold as Hillary Clinton wraps herself in the new mantle of oppression called "womanhood."