I've always thought the opposite. You never hear Republicans today praise Eisenhower's time in office, they only mention Reagan ad nauseum or at most praise Ike's pre-political military service. Perhaps they don't like the fact that he didn't dismantle any of the New Deal/Fair Deal programs and policies.
I think you're pretty off-base with that. The GOP is certainly proud of Ike.
Yet no Republican politicians nowadays will refer to themselves as an "Eisenhower Republican". They all refer to Reagan when they try to bolster their conservative street cred.
Reagan had more influence in shaping the modern Republican Party then Eisenhower did, so it is not a stretch that Reagan is referred to more.
