Ezra Klein, Vox - Trump is the most dangerous major candidate for president in memory. He pairs terrible ideas with an alarming temperament; he's a racist, a sexist, and a demagogue, but he's also a narcissist, a bully, and a dilettante. He lies so constantly and so fluently that it's hard to know if he even realizes he's lying. He delights in schoolyard taunts and luxuriates in backlash.
...Trump's path to power has been unnerving. His business is licensing out his own name as a symbol of opulence. He has endured bankruptcies and scandal by bragging his way out of them. He rose to prominence in the Republican Party as a leader of the birther movement. He climbed to the top of the polls in this election by calling Mexicans rapists and killers. He defended a poor debate performance by accusing Megyn Kelly of being on her period. He responded to rival Ted Cruz's surge by calling for a travel ban on Muslims. When two of his supporters attacked a homeless man and said they did it because "Donald Trump was right, all these illegals need to be deported," he brushed off complaints that he's inspiring violence by saying his supporters are "very passionate."
Behind Trump's success is an unerring instinct for harnessing anger, resentment, and fear. His view of the economy is entirely zero-sum — for Americans to win, others must lose. "We're going to make America great again," he said in his New Hampshire victory speech, "but we're going to do it the old-fashioned way. We're going to beat China, Japan, beat Mexico at trade. We're going to beat all of these countries that are taking so much of our money away from us on a daily basis. It's not going to happen anymore."
Trump answers America's rage with more rage... Trump's other gift — the one that gets less attention but is perhaps more important — is his complete lack of shame. It's easy to underestimate how important shame is in American politics. But shame is our most powerful restraint on politicians who would find success through demagoguery. Most people feel shame when they're exposed as liars, when they're seen as uninformed, when their behavior is thought cruel, when respected figures in their party condemn their actions, when experts dismiss their proposals, when they are mocked and booed and protested.
Trump doesn't. He has the reality television star's ability to operate entirely without shame, and that permits him to operate entirely without restraint. It is the single scariest facet of his personality. It is the one that allows him to go where others won't, to say what others can't, to do what others wouldn't.