Question for you, is that letter from 1952 or 1956 ? It was claimed somewhere that MLK, Jr. did vote once for Eisenhower in 1956 (as did NYC Democrat Congressman Adam Clayton Powell, Jr.). But that was the only noted time. He clearly voted for JFK in 1960, LBJ in 1964 and most assuredly had he lived until November 1968, for Humphrey.
If that letter is from 1956, that contradicts the claim I cited above.
It was from 1956, he would be talking about the upcoming 1956 election, but MLK tried to appear no-partisan generally, so if we look at the letter, he plays neutral on the surface, but with a strong “vote democrat” message.
“I am of the impression that
the Negro voter will go largely for the Democratic Party. I haven’t fully decided which candidate I will vote for. In the past I have always voted the Democratic
ticket.”
Either way, as you point out, he clearly states that he has always voted democrat, and he only has 3 elections to vote following this letter, and JFK and Lyndon Johnson clearly won his vote, so the 1956 election by itself doesn’t mean a whole lot, regardless of how he voted,
I don’t see how anyone can claim that MLK was a Republican.