Fine for people to voted uncommitted but jot sure why we don’t see more people voting in the republican primary to throw trump off balance.

You see that on occasion. My dad was registered Republican for many years in Florida just to vote in the primary for the less batshit option, and you have to be registered for a party to vote in their primary in Florida. In Minnesota, where I currently live, it’s an open-ish primary where I could have theoretically chosen to vote in the Republican primary but you have to sign something saying you generally agree with that party’s platform - and I can’t honestly say I agree at all with the Republicans, so it wouldn’t have been legal for me to vote in the Republican primary.