He would make it look like he was considering Romney for Secretary of State. He'd make Romney beg and plead. He'd make Romney show up a few times for dinner interview type things. He'd make Romney release a statement praising Trump. He'd drag it out interminably. He'd stage stuff like this.
And then, at the end, he'd yank the football away, Lucy Van Pelt-style.
Trump gave the Attorney General spot to Sessions rather than Christie because of Bridgegate. Giuliani is still sitting around with no reward for his loyalty, and no such scandals, and he clearly wants the job. Will Trump betray the loyal sycophant in favor of his enemy?
He has some reason to do it. Reach out to some skeptics, as he did by selecting Pence rather than, say, Gingrich. Remember, though, that he was forced to choose Pence because there was basically nobody else he could pick who would satisfy the party insiders by filling all of the gaps in his resume. That's why I predicted, back in April, it would be Pence. There are people in the party who would be happier with Romney, but there wouldn't be a revolt over Giuliani. So, maybe he's just pulling a Charlie Brown on Romney.
So, what will Trump do? No clue. But, call this the Lucy Van Pelt hypothesis.