Mentsch, when the toeva marriages issue was an issue, i heard the same from basically every gadol who spoke about it. Rav aharon shechter, rav hilel david…i can’t remember all of the names i heard back then.
i know of some chasidishe rebbes who endorse democrats in general, but their rabbonim who were considered gedolei yisroel, such as rav yechezkel roth, etc..have made no such pronouncements when the candidates support such things.
The reason is simple; how are we allowed to do something which will further chilul Hashem and promote violations of the Torah? Goyim must keep the 7 mitzvos, and these laws contravene them.
I’ve never heard a rational heter for voting for such a person. It’s not about chanifa, or praising the politicians… you’re allowed to do that to further our causes; you can honor reshoim for legitimate purposes. But you can’t do actions which will cause spiritual calamities to happen, and voting does that.