Interestingly, the only possible cure for Bannon/Trump, may be Bannon/Trump. 

If the center-left is convinced that B-T policies are wrong, then they should play the long game and let those policies go to their conclusions.

If they are convinced that Trump's trade rhetoric will hurt, and not help the middle class, then a few years from now, when the good citizens of Beattyville Kentucky (subject of a CNN piece on those trailerpark" folk who dream of Trump "restoring" their American dream) figure out they've been had, they'll turn on Trump. Or stay home.

If the center-left believes so strongly that Trumps immigration ban will hurt the economy but do nothing for security, then give that policy enough rope to hang itself.

For now, Bannon has the media's heads spinning like tops with outrageous trivia like crowd sizes, classic diversionary tactics while the real agenda is pushed through.

So, if you're convinced Trump is an idiot, maybe let him prove it.