I know my life will be worse if Josh Turek succeeds in pushing the rest of the Democrats to the right on trans rights; a vote for Josh Turek is a vote for Democrats to adopt anti-trans rhetoric and policies. The Party will be changed by his victory, but if he loses they'll think twice about nominating someone like him and that has an effect in 2028. Better to lose one seat than to potentially elect even more anti-trans Democrats in the future by giving them more of a foothold in the party.
The Democrats you vote for are the Democratic Party you are voting for, and when you elect bad Democrats you get a bad party.
Oh, forgot to say who I'm voting for: I'm writing in Zach Wahls, the pro-trans runner up in this primary. That gets recorded by the Party, just like wins and losses do, and they take it into account for future campaigns when they try to figure out what went wrong.