What did Donald Trump do today?

He refuted a claim nobody ever made with a lie.

At a White House event today, in the wake of an embarrassing miscalculation about voters' feelings about incarcerating children, Trump tried to put words in his opponents' mouths. 

I always hear that, "Oh, no, the [immigrant] population is safer than the people that live in the country." You’ve heard that, fellas, right? You’ve heard that. I hear it so much. And I say, "Is that possible?" The answer is it is not true. You hear it is like they are better people than what we have, than our citizens. It is not true.

Nobody has said that immigrants are "better people" than American citizens. But the Pew Research Center, researchers at SUNY-Buffalo, and dozens of other studies have said that immigrants to the United States are less likely than native-born citizens to commit crimes.

This is the second time in as many weeks that Trump has gotten the immigration-crime relationship backwards. In a tweet attacking German Chancellor Angela Merkel, Trump said, "Crime in Germany is way up. Big mistake made all over Europe in allowing millions of people in who have so strongly and violently changed their culture!"

In reality, crime in Germany was lower last year than at any point since 1992.

Trump hired undocumented immigrants as construction workers to build Trump Tower, is married to an immigrant who almost certainly worked illegally in the United States, owned a modeling business that instructed immigrants to lie to U.S. immigration officials so that they could work illegally, the ex-husband of an immigrant, and the grandson and son-in-law to beneficiaries of what he calls "chain migration."

Why should I care about this?

• It's bad if U.S. policy is based on things the president just made up.