The worst mistake Reagan ever made was making George HW his VP.
The Bushes are North Eastern country club Liberals, and they never had any business getting into power in the first place.
How few understand that. Reagan's mistake turned the "Reagan Revolution" into a mere a blip on the radar screen, a speed bump temporarily slowing down the Leftist insurgency.
How many understand that maybe the most important thing Trump can do is pick a VP who will be ready, willing, and able to walk into the presidency in eight years to FINISH what Trump started by DISMANTLING 80% of the $4 trillion mostly unconstitutional federal government? Otherwise, the "Trump Revolution" will also simply be a passing blip on the radar screen.
That's what happens when you pick a running mate to appease the establishment wing of your party. It's a good move from the standpoint of short-term political gain (so that you don't have your own party actively trying to sabotage your campaign, as establishment Republicans are doing to Trump), but in the long run it just helps empower the establishment. That's why I really hope that Trump doesn't try to appease the establishment of the GOP by picking a running mate like Rubio etc, because then the party hack can use the Vice Presidency as a launchpad for his own career and his family/allies, as the Bushes did with Reagan.