Ike was by most standards a moderate Republican, perhaps even a liberal one. Yet even a moderate Republican in the 1950's was willing to do deport illegals, something that not even many of the most "conservative" are willing to do today.
I'm not sure where the ones you list stood on the issue - they may have been the liberal wing of the GOP, but there was no political correctness or multiculturalism to infect their brains back in the 50's.
No, the PC of that day was opposition to “McCarthyism”, and Ike was a leader in that move; so was Prescott Bush. Bill Clinton praised Prescott Bush in a 1992 “debate” with the hapless GHWB.