What seems more likely

[Unconditional Surrender Truman]

Given how Lincoln felt about Andrew Jackson, I can't see him being terribly fond of Trump; claiming such makes him a Democrat is a bit of a stretch, however. In fact, one could argue that the Trump coalition has in fact restored the Republican Party to the it's original state by resurrecting the alliance between working-class voters and wealthy capitalists that allowed Lincoln and Garfield to win their respective elections.

The problem with these sorts of hypotheticals is that they attempt to divorce historical figures from the context in which they lived and drop them un-inoculated into the 21st century. It's probably safe to say that all three of these men would be surprised by the present state of their party, but then, they would also be surprised by female voters and telephones.