ISTM that the real power of a Trump comes from creating turnout.
In 2012, 58.2% of eligible voters actually voted. Of those who did vote, it came out Obama 51.1% Romney 47.2%. IOW, the actual vote was 29.7% Obama, 27.5% Romney, and “I didn’t bother to vote” came first with 41.8% of the eligible voters. That is HUGE.
Any candidate who can get out a big chunk of the “I don’t vote” crowd only needs to skim off a smidgen of the mainstream candidates’ typical voters to win.
Total turnout was unusually high in 2008 when Obama was first elected and the typical explanation was that he energized a lot of the “I don’t votes” to vote for him. 2012 the effect on turnout was much less pronounced and Obama’s margin of popular vote victory was less as well.
Bottom line: 2008 taught both sides that unlike the past where elections were won in the middle, now elections are won by getting out the “I don’t vote”.
Anyone campaigning as a charismatic protest outsider candidate, regardless of ideology or affiliation has a heck of a chance of energizing the true swing vote, the one that normally doesn’t vote at all.
Barring a divine intervention by the Kochs’ wallets, I see Trump having a real run at the nomination and the election as well. Note I’m not suggesting that will be a good thing. But I see it as a very plausible thing.
For all the talk about “anybody but Trump”, there’s also a lot of people in this country who are “anybody but Hillary” voters. An election between those two would largely become on each campaign shrieking “Vote or else the Boogey (Wo-)man will win!!”
If the Republican Establishment gets the idea it’ll be able to control Trump or at least stymie his craziest efforts, they may well get behind him as the best way to drive voter turnout through the ceiling and therefore win. And high partisan turnout also has a way of delivering lots of Congressional seats, governorships, and state houses.