President Donald Trump used the attempted New York terrorist attack this week to renew his call to end chain migration. Thats the term immigration restrictionists use to describe allowing U.S. citizens and legal permanent residents to help their family members immigrate to this country.

The president and his allies insist without evidence that this kind of immigration is a threat to the nation because it lets in suspect people. They argue that limiting Americans ability to bring in family members will help prevent attacks like Mondays incident, which was allegedly perpetrated by a legal permanent resident from Bangladesh whose uncle, a U.S. citizen, had sponsored him to come to the U.S. in 2011. (The investigation so far suggests he became radicalized some years later.)

The fact is that Trump, like millions of other Americans, has personally benefited from the same sort of migration he now decries.

If the U.S. didnt allow immigrants to follow their family members, Trump might have led a poorer and lonelier life. Some of his ancestors might not have come to the U.S. to join family, long the most common form of immigration. His in-laws options for joining his wife, herself an immigrant from Slovenia, in the U.S. would have been notably limited. His businesses could not have hired certain talented workers. And the president himself might not have been born in the U.S. at all.

Trumps ancestors followed family members to the U.S.