Percentage of the population vote based on letter next to the candidates name?!

[RINO Tom]

This question is hard to answer, actually, as you can't just look at the totals, IMO.  Each election, there are chunks of the population who "swap" with each other (e.g., Romney-Clinton and Obama-Trump electorates) and then a chunk that pull another switch four years later depending on the total national environment (e.g., Obama-Trump voters coming home or further Romney-Trump-Biden switchers).

So, it's hard to come up with a good point in time to evaluate these people's willingness to vote for the other party.  For example, it's hard to know if a Romney-Clinton voter was a complete Republican hack until 2012 and Trump turned him off so vehemently that he left or if she was always sort of a "moderate conservative" who was primed to cross the aisle for the right (or wrong) candidate.  The group obviously consisted of both.  To answer super simplistically, I would say that in general about 80-85% of Republicans are unwaveringly loyal and 75-80% of Democrats are (though this might be shifting ... the Democratic Party isn't exactly the "big tent mess" it was when Will Rogers had his funny quote).  I'd say Independents are probably about 60-65% "hacks in disguise" and 35-40% swing voters (who still STRONGLY prefer one party over the other).  These are conservative estimates to avoid hyperbole.