How about Martin O'Malley for POTUS 2020?

[Jim Lane]

44. O'Malley's experience is one of his strong points.

You write: "O'Malley really endeared himself to me during the campaign, but I wonder about his experience...."

O'Malley spent eight years as a governor. The electorate seems to like that experience. From 1976 through 2004, seven of the eight elections were won by current or former governors. The exception was Bush 41, who had other executive credentials as having headed a federal agency (the CIA) and been Vice President.

The string was necessarily broken in 2008, when each major party nominated a sitting Senator who'd never been a governor. One of them had to win. A former governor lost in 2012 but by then his opponent had four years of executive experience as President.

I agree with your basic point about the Trump effect, that "the pendulum will swing back the other way and people will want someone experienced." O'Malley's record as Governor, preceded by two terms as Mayor of Baltimore, will look pretty good.