[Austin Willard Wright]

Hamilton wasn't a Whig but he almost certainly would have become one had he lived long enough. It was his ideological home....though he probably wouldn't have liked Lincoln's or Harrison's log cabin routines.

[William McKinley]

Quite possible. It is also very likely that had John Adams lived that long, he would have become a Whig. And the same goes for George Washington. But that is neither here nor there. They didn't, and if they had they would likely have influenced the party as much as the party would have influenced them.