It seems to me that Obama (and Clinton) were more about adjusting to change (for all their warts). Trump, seems to be all about reviving a mythical past - as you say with white guys on top that is neither possible nor sustainable. 
Why didn't voters simply clean out the Republican obstructionists?  First of all the popular vote does mean something, It means the young urban, relatively affluent, watchful and educated will not stand for a "Trump campaign" style administration. These are the folk who walk away from the irrelevant but will stand for what they really value. The vast majority will stand with them, and not the back-woods militias. 
The challenge to the "popular" majority - of whatever stripe, it seems - is to see the vast majority of those who "trumped" for what they are - good decent people who warrant respect rather than being lumped into the mistake they made and listen to the point they made.
It sorta like us and the hierarchy: it's up to the real people to become civil.