Donald Trump's acceptance speech was one for the history books, under "Prime examples of American infamy". It was a terrifying speech in the clinical sense of the word, it was meant to terrify people into voting for him lest they suffer the consequences of not doing so, and it was meant to terrify those voting against him and reminding them, as Steve M says, that Donald Trump can very well win this thing in November.
It isn't just that Trump's speech successfully tapped into the anxieties of many Americans -- it's that the entire convention did, in between all the things that were so fascinating to political insiders. And while the four days of speeches, up to and including Trump's own, didn't provide solutions beyond "Donald Trump will magically fix everything because he's all-powerful," they did offer up a scapegoat for all the world's ills: Hillary Clinton, the worst person in the world.
I'm not supposed to worry about this because the presidential electoral is supposedly etched in stone: Yes, older whites always vote Republican, and whites are a majority, but they're a dwindling majority; Barack Obama built a coalition that can't lose a presidential election anymore. But Obama's coalition never stopped liking him; his approval/disapproval numbers always hovered within a few points of 50-50, and those who approved of him really admired him. Hillary Clinton, by contrast, has a 40%/58% favorable/unfavorable rating right now, according to the average at Huffington Post's Pollster. To win in November, she needs the votes of a lot of people who simply don't like her and don't trust her. So why are we so certain the Obama coalition will turn out for her?
In the Obama years, we've seen dogma-driven Republicans expand their near-monopoly on white people's votes from the South to supposedly blue parts of the North -- see the governors' mansions in Maine, Wisconsin, Michigan, and Ohio. I know -- they won because the Democrats' presidential electorate doen't show up in off years. But which electorate will show up for Hillary Clinton if she doesn't get her disapproval ratings down?
The answer to those questions was provided by Trump himself in one of his ad-libbed parts of his speech when he promised to end Muslim immigration into the United States:
"We don't want them in our country!"
He was speaking about Muslims. But you can apply that to any group of Americans not sufficiently Trump-approved. That phrase doesn't just describe the Trump campaign, but the entire Republican party. Every single person planning to vote for Donald Trump in November (and that's going to be at least sixty million of your friends, neighbors and co-workers, guys) has a "them" that they want out of "our" country.
Put that on a bumper sticker. Hell, I'm sure people will. But that's what Donald Trump represents, and that's what the people voting for him want. It doesn't matter that some of the people supporting Trump are the very people other Trump supporters want America to be rid of permanently.
It's to stop this man that the Obama coalition will turn out.
If we don't, well, we end up the "them" in this equation, now don't we?