And would it have made a difference had he been more proactive pointing out Trump’s shortcomings?
I’ll save you thinking about your questions:
“Would that have been different had he been the first one in?” Nope. Trump was the last to enter in 2016, didn’t do the 15 Dwarfs any good.
“And would it have made a difference had he been more proactive pointing out Trump’s shortcomings?” Would have made him lose by even more. Trump supporters know about all his shortcomings, thanks to the DNC, Biden’s people, and the media. They get pissed off listening to other Republicans use the talking points of the DNC, Biden’s people, and the media.
The bottom line was that the nomination was Trump’s for the taking if he wanted it, and he wanted it. Even Reagan, at his prime, would have had trouble this year against Trump.