I think what McCain was doing was simply recognizing that Trump has absolutely ruled in this race, since three weeks after he joined. Every single poll.
He tried to endorse a bunch of other weenies, but Trump is in charge.
You know he would be all over Trump, bashing him with gusto, if he were the slightest bit vulnerable.
Didn’t Trump kick off his campaign by trashing John McCain’s service record?
I think he waved his arms around while he was doing it also...:^)