We were registered Democrats our entire lives, until Trump became President. We quickly learned that we were on the wrong side of life (although we consider ourselves moderate conservative, we are pro-choice and are not hardcore religious...but that's a subject for another day). We instantly became Trump fans...and we're Mexican/American! I was informed that if we're independent, we can't vote for a Republican Presidential nominee. So, do we have to register as Republicans in order to vote for Trump?
Edit: Forgot to add we are in California!
That's not quite the case in Michigan. You don't have to declare and aren't asked your party, but you can't split your ticket in the primary. If you vote for any Republican, you can only cast or withhold votes for Republican candidates and vice versa or the ballot will be counted as spoiled.