[No One Special]

The article is very long. There's much more at the link. Sort of silly to ask what might have been except as an exercise in how history hinges on many things. The author of the article wrote a biography of Greeley in 1950. Here is info about him on Wikipedia.

He was a Democrat. LOL.

[Theodore R.]

Greeley had been a Radical Republican right up until the Democrats endorsed his co-nomination by the Liberal Republican Party in 1872. Though a Radical, he had raised money for Jefferson Davis’ defense too. He was a man of contradictions. Had he been elected, he would have never become president because he died before March 4, 1873.