“I do think McCain helped Romney in ’12 and think Romney would definitely help any candidate,” former Romney political strategist Stuart Stevens told The Daily Caller in an email after stipulating that he doesn’t know who the former Massachusetts governor intends to endorse, or even if he intends to endorse in the primary at all.

“McCain and Romney, along with Lindsey Graham, remain popular in the Granite State – particularly among the more establishment GOPers,” Wayne Lesperance, a professor of political science at New England College in Henniker, N.H., explained to TheDC. “So, their endorsements, if taken together for the same candidate could help identify an establishment candidate around whom voters could rally.”

Of course, Rubio would deny he is an establishment candidate – and Lesperance sees Christie as the more likely beneficiary of a McCain-Romney endorsement. Rubio’s communication’s director Alex Conant told TheDC that the campaign has nothing to say about Rubio’s efforts to woo McCain and Romney.

But if Rubio is not a card carrying member of the Republican establishment, he is at least seen as a candidate who can bridge the establishment/anti-establishment divide. He is certainly a more acceptable candidate to Washington politicos and many longtime GOP donors than either Cruz or Trump.