This is false
Every county in my state always votes red. Due to the way elections are held in this country, it does not matter how I vote. I could vote for Harris, on the tiny chance that enough others will as well, or I could vote 3rd party, and at least increase the percentage of voters doing that so that it doesnt seem as useless next time. Hell, I could vote for trump and there would still be no difference.
Don't alienate your allies if you want them to stay allies