What did Donald Trump do today?

He traveled to El Paso to lie about El Paso.

Trump held a campaign rally in El Paso, Texas this evening, where he repeated a lie about crime and border fences that he debuted in his State of the Union Address. During that speech, he made this claim:

The border city of El Paso, Texas, used to have extremely high rates of violent crime — one of the highest in the entire country, and considered one of our nation's most dangerous cities. Now, immediately upon its building, with a powerful barrier in place, El Paso is one of the safest cities in our country.

In reality, before border fences went up near El Paso in 2008, it was one of the safest cities in the United States, according to the FBI.

Trump may simply have assumed that all border cities are dangerous, or it may have been a deliberate lie. Treating all potential migrants from Latin America as criminals has been a central theme of his campaign since its very first day, but in the real world, immigrants are less likely to commit crimes than native-born Americans.

The city's current Republican mayor, Dee Margo, gently corrected Trump yesterday, prompting this response from Trump tonight:

And I've been watching, where they've been trying to say, "Oh, the wall didn't make that much," well, you take a look at what they did with their past crimes, and how they made them from very serious to much ser—you take a look at what the real system is, I spoke to people that have been here a long time, they said when that wall went up, it's a whole different ballgame. Is that a correct statement? Whole different ballgame. I'll give you another example, and I don’t care if a mayor is a Republican or a Democrat, they’re full of crap when they say it hasn’t made a big difference.

But again, in the real world, El Paso has been one of the safest cities in the country, long before any border fence went up nearby.

Trump did not say who were the "people that have been here a long time" that he spoke to, presumably in the 30 minutes between arriving at the rally and going onstage.

Why should I care about this?

• Facts don't change just because a president wants them to.

• Asking people to pretend that false things are true, even when they know better, is what authoritarians do.

• Treating all members of a group as though they had the same bad characteristic is pretty much the definition of bigotry.