Ike was popular but the GOP was not.
The point. Just look at the results of the 1952 and 1956 Presidential elections. Eisenhower won Massachusetts and Rhode Island, the only two Northern states that did not go for Herbert Hoover in 1928 (then fairly recent history)... and he is the only Republican since 1924 to win both Massachusetts and Minnesota in the same Presidential election, and he did that twice. (Nixon got a 49-state landslide in 1972 without Massachusetts, and Reagan got a 49-state landslide in 1984 without Minnesota).
Eisenhower manifestly won millions who did not play golf. It is true that Republicans had yet to break into the Southern suburbs, but not for any fault of their political competence; the South was then much more rural in population. The South had few suburbs, and its cities were much smaller.
What did Ike do right? He posed no threat to the New Deal, and he did not jump onto the Red-baiting bandwagon of Senator Joseph McCarthy. Other Republicans railed against the New Deal and jumped onto the Joseph McCarthy bandwagon -- and they would pay a political price for such folly. Defeat.
Such played a role. Democrats played up the New Deal as a back-up to an unregulated market.