It is often said Kennedy, Johnson, Truman and others could no longer be Democratic Party. Rachel Maddow, MSNBC, once quipped "I'm undoubtedly a liberal, which means that I'm in almost total agreement with the Eisenhower-era Republican Party platform."
I actually went back and found the 1952 Republican Platform on which Eisenhower ran. It is remarkably relevant today's to the problems caused by the current administration.
https://www.presidency.ucsb.edu/documents/republican-party-platform-1952