I don’t know how to tell people that the only way to win, to truly win, is to have principles and bring people along to rally behind advancing those principles. Electoral politics is no exception to this truth. If you elect someone who does not adhere to, or advance, your principles, you cannot win.
If you are saying “that is not a principle I care about”, then you are, at least, being honest. But you cannot say “I will elect a person who does not honor this principle, and they will advance this principle.” That does not happen. It cannot happen.