What did Donald Trump do today?

He got confused about which kinds of immigrants he gives jobs to.

In recent days a nasty fight has broken out in the Trump camp over the question of H-1B visas, which are used to allow businesses to hire highly skilled foreign workers. They are common in the tech industry, and so Trump's "advisor" and patron Elon Musk has been fighting with Trump's more extreme-right nativist supporters like Laura Loomer over whether they should be restricted or expanded. Musk called Trump supporters who thought they were voting for restricted immigration "contemptible fools," while banning people who disagreed on Twitter, which he owns.

(Musk, who has since become a citizen, worked illegally in the United States—something he almost certainly has in common with Trump's third wife, Melania.)

Trump, who has been uncharacteristically deferential to Musk even as his staff seethes at the would-be "co-President," weighed in on his side today. Trump claimed that he, too, hired many H-1B employees. But that is not true. 

The Trump Organization does hire a great many foreign workers—even now, after Trump promised not to—but they are mostly if not entirely on H-2B visas, which is an important distinction. H-2B visas are for guest workers who do not possess rare technical skills, but who fill jobs where there are simply not enough American workers available.

Trump's businesses have used H-2B visas to fill jobs at his golf courses as bar staff or janitors, for extremely low wages. They are typically "advertised" for a day in a single newspaper, after which Trump's businesses claim there are no available American workers. (Sometimes, Trump has failed to offer any evidence that he tried to hire Americans at all.)

The advantage for Trump to using H-2B visas is that the workers hired have no choice other than to take whatever Trump's businesses give them, whatever that may be. It would be practically impossible for a guest worker to transfer the visa to another employer, or to sue for damages. That means a worker who protested mistreatment or wage theft or sexual harassment could simply be fired—and these are all chronic complaints at Trump businesses. Any guest worker who was fired would then be forced to leave the country at their own expense.

The only workers more easily exploited than H-2B are those with no legal work documentation at all. Trump, who campaigns as an immigration hardliner, has been repeatedly caught hiring such workers. His response has been to blame underlings (including his own children) while simultaneously claiming that everyone does it.

Why does this matter?

• Someone who campaigned on immigration reform should know something about immigration law.

• Business owners, like presidents, are responsible for what happens on their watch.

• "Everybody does it" is not a valid criminal defense.

• People who voted for Trump because of his campaign promises on immigration might have expected him to keep them.