My line of reasoning is along the lines of Lincoln's Team of Rivals concept.
Did Lincoln's team of rivals consist of people who refused to support him in the general election once he'd won the nomination?
He did appoint Seward to State, Chase to Treasury, Bates to Justice, who were all rivals for the nomination.
But didn't all of them support Lincoln in the general election once he was the nominee? Romney is the opposite of them in both respects: He didn't run against Trump for the nomination, but he did refuse to endorse Trump in the general election.
I did say there were similarities, Seward, Chase, Bates tried to defeat Lincoln for the nomination, but did support him afterwards, whereas Romney worked for the defeat of Trump for the nomination, though of course Romney was not a candidate himself, but indeed Romney did not support Trump in the election. So true.
Similarities but obvious differences as well.