How running a business is not like running the Government.

What Trump's business experience actually is, how he got a huge head start, and how prior success has gone to his head in dangerous, manic ways.

How obvious his behavior is as a sign of severe insecurity and narcissism, and how unreliable and easily swayed such people are.

How there are no ways to 'get the jobs back' from China or anywhere else, how free trade is pretty much universally seen as an overall positive by economics, despite what the surface perceptions are by those who don't understand economics, and how the high tariffs Trump proposes would be disastrous.

How the problems with foreign policy or trade are not due to a lack of 'tough negotiating'. And how in general the machismo and aggressive posture is already destabilizing our relations with some foreign nations, simply because he's the presumptive nominee of one of our parties.

How immigrants actually commit less violent crime on average than the population at large, and how economic knowledge, again, widely diverges from populist/nativist thinking about 'taking our jobs'. Even illegal immigration is of benefit.

How completely impractical deporting all illegals is, and how absurd, costly, impractical, and ultimately ineffective a wall on the Mexican border would be.

How Trump supporters' anger and despair over their life and/or financial situation makes them desperate to believe Trump is what he claims ("If he's not, then what are we going to do?"), while the real reasons for their problems are likely due to a slew of complicated factors that don't make exciting politics, and cartainly not the easily-blamed boogeymen of immigrants or foreign countries Trump give them (and how those culprits have been used by politicians to gain favor for throughout the world and throughout history, including Hitler and Mussolini).

How closely Trumps cult of personality and exploitation of people's woes and economic troubles resembles that of Hitler and Mossolini.

How people's desperation makes them want to believe Trump can do all the things he claims, because they need it to be true.

How irrational we are as people, and how our minds lie to us. Trump is playing the salesman just as he has for his image and properties his whole career. He's basically the ultimate politician as long as you don't ever think about anything he says too deeply.

How Trump's antics appeal to a deep, primal, monkey part of our brains that persuades us more than we want to believe it does.

How, a humans, we want to be right, and how we select what we want to hear in order to make ourselves feel more right: http://www.politico.com/magazine/story/2015/12/donald-trump-2016-evolutionary-psychology-213444

How supporting Trump requires justifying that every bit of the massive negativity he has received is due to some boogeyman (liberal media, 'the establishment'), no matter what form it takes or how blatant it gets.

How, once you realize that there is practically nothing you could not justify to yourself somehow, in your desire to want to like Trump; No scandal, no news story, no absurdity that could come out of his mouth, that you could know by that alone that you are lost, and not thinking rationally.

I could go on, but I hope that's enough.