MLK was neither a R or D, he tried to stay independent, but leaned more Lib, oddly most of the the civil rights bills were brought up by The R’s including the civil rights bill of 1960 under Ike. (with higher % R vote then D’s)
March 24, 1960 by a vote of 311-109.[3] [4] 179 Democrats and 132 Republicans voted Aye. 93 Democrats, 15 Republicans, and 1 Independent Democrat voted Nay. 2 Democrats and 1 Republican voted present. [5]
Also, the % of Republicans voting for it far exceeded the % of Dems who did.