Republican presidential candidate Donald Trump. (Jabin Botsford/The Washington Post)

It’s common to hear students of the polls say things like: “Hillary Clinton will win the election unless some unexpected event pushes people to Donald Trump.” The idea is that Clinton’s strength among Latinos, African-Americans and women will, all things being equal, allow her to overcome whatever advantage Trump builds among white men unless something shakes the race up.

In this scenario, one of the top candidates for the “unexpected event” is a terrorist attack. A widely-held view is that in such circumstances, Trump’s I’ll-break-the-crockery strong man image would appeal to many voters who were afraid.

Tragically and horrifyingly, this theory has been put to the test in the wake of Sunday’s Orlando massacre, the deadliest mass killing in American history.

While speaking in Manchester, N.H., on June 13, Republican presidential candidate Donald Trump said, if elected, he would ban immigration from “areas of the world where there’s a proven history of terrorism against the United States, Europe or our allies, until we fully understand how to end these threats.” (Reuters)

What the they’ll-swing-to-Trump theory did not take into account was the probability that Trump’s response to a terrorist episode would be so offensive, so over-the-top, so redolent with prejudice, so conspiracy-minded and so, well, un-American that far from rallying to Trump, even more voters would flee from his candidacy in alarm. Trump’s speech on Monday at St. Anselm College in New Hampshire was, if anything, worse than even his harshest critics might imagine he would give. It channeled traditions not of America, but of Europe’s far right.

Trump proposed, as the New York Times put it, “sweeping measures against Muslims that pay little heed to American traditions of pluralism.” He expanded his proposed ban on Muslim immigration to a ban on immigrants from from any place in the world with “a proven history of terrorism” against the United States and our allies.

And as The Post editorial board wrote, “he chillingly accused Muslim-Americans of complicity with terrorists.”

“The Muslims have to work with us,” Trump said. “They know what’s going on.” They knew, he claimed, that the Orlando shooter “was bad.” “They knew the people in San Bernadino were bad. But you know what? They didn’t turn them in. And you know what? We had death and destruction.”

His speech was also riddled with falsehoods. To pick just two rather important ones: He said the Orlando shooter was “born an Afghan.” Oman Mateen was born in New York City. And he charged that there was a “tremendous flow” of Syrian refugees to the United States when, as the Times pointed out, “just 2,805 of them were admitted into the country from October to May.” I have only scratched the surface here of Trump’s factual inventions.

Oh, yes, and he earlier implied that President Obama had a dark hidden agenda. “We’re led by a man that is either not tough, not smart, or he’d got something else in mind,” Trump said Monday morning on Fox News. “There is something going on.”

House Speaker Paul Ryan repudiated Trump’s Muslim ban on Tuesday, telling reporters: “I do not think a Muslim ban is in our country’s interest,” Ryan told reporters at GOP national headquarters. “I do not think it is reflective of our principles, not just as a party but as a country.” Ryan added: “The vast, vast majority of Muslims in this country and around the world are moderates. They’re peaceful, They’re among our best allies, among our best resources in this fight against radical Islamic terrorism.”

It’s good that Ryan said these things, but you have to ask: How long can he and Senate Majority Leader Mitch McConnell maintain their endorsements of this  frightening and dangerous demagogue? What will be too much for them?

Perhaps the polls in the coming days will prove me wrong, but my hunch is that voters will recoil from a man so eager to exploit national pain, so willing to scapegoat entire groups of people, so ready to traffic in groundless conspiracy theories, and so indifferent to whether what he says is true or false.

It is a cliché of political rhetoric, but no less true for that: We really are better than this.