Frankly, I don't consider mid-40's to be too young. Late 30's for a Veep, either. I do consider 2-3 years of being a senator to be too inexperienced, but Kennedy didn't have all that much more than that. The fact that he appears to be a personable asshole and toady would disqualify Vance from my point of view (and I really liked Hillbilly Elegy)
It's time to respect younger people and new ideas. Really. Madison was in his 30's and Jefferson in his 40's during the writing of the Constitution. Yes, Franklin was old, but he was about the only one.
Wendy P.