I'd have to look it up but I seem to remember Adali Stephenson always seemed to be the Democrats candidate during that time, so it may have been him. I also understand Eisenhower was courted by both Republicans and Democrats, similar to Colin Powell, which was one of the reasons the media fawned over Powell.
Adlai ran against DDE both times. You're right...Eisenhower was courted by both parties because of his immense popularity as a general. Not much was known of his politics.
The first time they ran against one another, there was a perception that Adlai had a chance. He lost badly. The second time, he was a sacrificial lamb as DDE was very popular and the dems realized no one could beat him.
Adlai was an attractive, charming man and not very much like the democrats of today.