Donald Trump Is Wrong on Immigration, Sanctuary Cities, and Refugees. Here Are the Facts.

A selection of Reason TV videos.

The shocking ascent of Donald Trump to the head of the GOP field began with a single, audacious, visually arresting campaign promise: To build a giant wall along the U.S. southern border and force Mexico to pay for it.

Trump didn't get to that "big, beautiful wall" until week four of the campaign, but he demonized Mexican immigrants when announcing his candidacy:

When Mexico sends its people, they're not sending their best. …. They're sending people that have lots of problems, and they're bringing those problems with us. They're bringing drugs. They're bringing crime. They're rapists. And some, I assume, are good people.

In later speeches, Trump compared Mexican immigration to the Mariel boatlift, in which Castro intentionally released criminals from Cuba's prisons and sent them to South Florida along with refugees escaping communism.

In the video below, professor Joel Fetzer explains why the comparison isn't apt, pointing out that migration from Mexico has been on a downward slope since at least 2005. Fetzer also debunks a number of other immigration myths: that immigrants increase unemployment among natives; that they increase the violent crime rate; and that they're a drain on public resources.

Trump cashed in on an emotion-laden issue that most Americans, including Republicans, didn't prioritize until he entered the race. To do so, he capitalized on a couple of tragedies that bolstered his case.

The first was the shooting of Kate Steinle on San Francisco's Pier 14, allegedly by an illegal Mexican immigrant named Juan Francisco Lopez-Sanchez. The shooting occured on July 1, less than a month after Trump began his campaign. The timing couldn't have been better, and Trump doubled down on the issue—though he didn't bother to personally call Steinle's family and offer condolonces or support until Steinle's brother called him out in the media.

Watch the video below to learn why Trump is wrong to use a young woman's tragic death to criticize sanctuary-city policies. New immigrants, including illegal immigrants, are less likely to commit violent or property crimes than U.S. citizens, and there's little evidence that crime rates are higher in sanctuary cities than in non-sanctuary cities.

Trump seized another political opportunity in the wake of the terrorist attacks in Paris by declaring that he'd put a halt to all Muslim immigration "until we figure out what's going on."

Again, Trump is wrong because the U.S. government does indeed have a pretty good idea about "what's going on." For a glimpse at the multi-tiered bureaucracy refugees must navigate to arrive here, take a look at this next video.

Refugees in general, and Syrian refugees in particular, already are among the most intensely scrutinized immigrants to enter the U.S. Despite Trump's proclamation that the refugee migration might be "the greatest Trojan horse of all time," the fact is that terrorist attacks in the U.S. by and large have been carried out not by refugees but by people here on student visas or naturalized American citizens.

The facts contained in these videos may be unpopular, as indicated by the overwhelmingly negative feedback in the YouTube comments sections. And they probably won't sway the views of Trump supporters willing to stick with him even when he openly admits he doesn't really believe what he's saying.

But in a country that relies on immigrants to maintain a vibrant, dynamic economy, and a healthy voting populace that can act as a bulwark against the rise of authoritarian strongmen, a clear and constant repetition of the facts can at the very least provide solid ground to retreat to when the hazardous muck of Trumpism starts to sink away.