Strom Thurmond endorsed Ike in 1952.
Did he not in ‘56?
In addition to what DINGO Joe said, from the Wikipedia article on the campaign:
The Eisenhower administration had supported the Brown v. Board of Education ruling in 1954; this ruling by the U.S. Supreme Court ended legal segregation in public schools. Meanwhile, Stevenson voiced disapproval about federal court intervention in segregation, saying about Brown that "we don't need reforms or groping experiments."[8] This was an about-face from the national Democratic party platform's endorsement of civil rights in the 1948 campaign. Although Eisenhower "avoid[ed] a clear stand on the Brown decision" during the campaign,[9] in the contest with Stevenson, he won the support of nearly 40% of black voters; he was the last Republican presidential candidate to receive such a level of support from black voters.
https://en.wikipedia.org/wiki/1956_United_States_presidential_election#General_electionI wonder if Stevenson's scaling back the national Democrats' commitment to civil rights was him throwing a bone to the Dixiecrats to keep them in line, especially since he had picked the more progressive Estes Kefauver in 1956 as opposed to the segregationist John Sparkman in 1952 - which clearly didn't stop Thurmond's endorsement of Ike that first time around!
Also, it's important to remember that Eisenhower's 1952 campaign was actually seen quite favorably by southern conservatives like Thurmond, and other conservatives (in
both parties) who wanted a more muscular, militaristic anti-Communist foreign policy - as opposed to the more traditional non-interventionist anti-Communism of Republicans like Robert Taft. The fact that Truman had been moving more decisively in support of civil rights (desegregation of the armed forces) + Humphrey's civil rights speech and DNC platform plank which instigated the Dixiecrat walkout in 1948 also obviously pissed off Thurmond and other segregationist Democrats.
As for foreign policy (and this is key to Truman being so unpopular by the end of his Presidency)...well, events like the USSR getting the bomb, "losing China", the Korean War, Truman's firing of General MacArthur, the trial of the Rosenbergs, and the rise of Joseph McCarthy all seemed to strengthen support for a new, aggressively
interventionist conservative foreign policy of "rollback" (brought to you by the Dulles brothers) - and who better to head that policy than the likable, massively popular war leader General Eisenhower? Plus, he had picked as his running mate the populist Republican from California who brought down Alger Hiss in the House, red-baited Helen Douglas to a Senate seat, and was consequently the bane of liberals everywhere.
After having both the Presidency and Congress dominated by the despised New Deal Democrats for two decades, the Eisenhower/Nixon ticket seemed to be about as good as it got for many hardline anti-Communist conservatives in 1952, some jaded Taft holdouts notwithstanding.
Also important to note that
the "Sun Belt" conservatives of the South and West (again, still well-represented in both parties at this point) were particularly on-board with the new, militaristic and muscular anti-Communist foreign policy. In addition to Thurmond (South Carolina), you had Barry Goldwater (Arizona) as a solid Eisenhower man at the 1952 RNC, and Ronald Reagan (California) breaking with the Democratic Party for the very first time by joining "Democrats for Eisenhower." And for what it's worth, Ike won Texas and Florida both times and Louisiana the second time. Intriguing...
