Quick: When you think back on the past half-decade of political campaigns, what do you miss? Is it pointless celebrity vanity campaigns? Irresponsible culture war fearmongering?

Yes, which is why I wanted to read your article, which clearly engages in such fearmongering. :-)

Buckle up, friend: Caitlyn Jenner is running for Governor of California, and her first major policy recommendation is banning trans girls from sports.

I hardly think a quick question while getting into her vehicle qualifies as a "major policy recommendation." Plus, you should not lie: she did not recommend banning trans girls from sports. What she said, quickly while being ambushed on getting into her car, was:

“That’s why I oppose biological boys who are trans competing in girls’ sports in school. It just isn’t fair. And we have to protect girls’ sports in our schools.”

Well, she's right. We're now up to what, a dozen peer-reviewed articles, like this one, and this one (lead researcher here was a transwoman herself) that show that hormones cannot -- ever -- remove the physical advantages enjoyed by men in Things Athletic.

Girls’ sports are not in danger; trans children are, and some of them are dying, or trying to die, because of the discriminatory legislation currently being aimed their way in over thirty states.

Ooh. A list. Let's taken them one at a time.

1) Correct. Girls sports, in general, are not in danger; although if sex-based athleticism is to be ignored, it begs the question as to why we have girls sports at all.

However, in come cases, the physical well being of genetic girls IS in danger, and most certainly the hard work put in by genetic girls to earn college scholarships may also be. Both are unacceptable to those who are non-ideological on this issue.

2) Hm. You really want to argue that if trans girls have to compete with the guys rather than the girls, their lives are in danger?

You sure you want to die on that hill?

So Jenner, who is a trans woman and an athlete, is reciting ugly, irresponsible rhetoric about transfeminine athletes, without even rewording her GOP talking points.

There’s nothing ugly or irresponsible about what she said. She said it was a question of fairness, which the aforementioned research articles provide backing for. And that women's sports are worth protecting. Nothing ugly or irresponsible about either.

(Just as a sidenote: People can both read and know the definition of words. When you claim that some words are ugly and irresponsible, and by any standard of common usage and logic they are neither, it detracts from whatever point you are hoping to make.)

"A lot of cis people with transphobic opinions about student athletes will probably be emboldened to embrace them because, hey, Caitlyn Jenner is trans, and she said it was okay. "

Sure. Just as Democrats used to latch on to John McCain when he opposed Bush's tax package and (more recently) the abolishment of the ACA, political entities always gravitate towards members of a "side" when they seem to break with their expected status quo. This is how politics always has been and always will be. Nothing new to see here folks, move on.

"Now Jenner is using that platform to spread misinformation and bigotry"

(Searches article. Finds no examples of either.)

"Jenner is going to become the subject of a lot of ugly, transphobic commentary and Twitter jokes in the coming months..."

Maybe, and if so, your fears about the supposed size of her platform will be negated. However, it is also possible that she shows herself to be a serious candidate, and in doing so, people see that the fact that she is trans is not particularly relevant in the job she aspires to do. The more Americans which come to that realization would bode well for the way trans people are perceived in the future.

"I am less angry at Caitlyn Jenner than I am at the fact that, as of this week, the single most visible trans woman in politics is Caitlyn Jenner."

Well, that's not her fault now, is it? :-)