There is no question that Ike's work as Supreme Allied Commander in North Africa and Europe directly led to defeating Germany. (We're talking about USA politics, so I won't say anything about the Soviet Union's larger role in defeating Germany.) Ike was an outstanding general and diplomat during WWII. As a politician during the 1950s, he was not nearly as good.
For example, he's given credit for warning the country, during his farewell speech, about the dangers from the growing power of the Military/Industrial Complex during the Cold War. But he also was responsible for the rapid growth of the M/I Complex during his 8 years in office.
When Ike took office in 1952, he failed to say anything to criticize Joe McCarthy's reign of terror in Washington. He got that wrong.
When his own Vice President Tricky D!ck Nixon ran for president in 1960, Ike was (much later) given credit for never endorsing Tricky D!ck. He got that right.