Pundits trying to explain Donald Trump’s success frequently discount the importance of immigration. Wednesday night’s debate performance suggests even Trump doesn’t get it.

I hesitate to predict anything about his polling, since smarter people than me have proven embarrassingly wrong. But by seeming to revert to the billionaire consensus that we need to increase immigration, Trump might have sowed seeds of doubt in some of his supporters. Sure, he’ll explain away his anti-worker comments, but that’s what politicians do, not anti-politicians like Trump.

What’s more, Trump allowed Marco Rubio — Rubio, for Pete’s sake — to get to his right on immigration, even as Rubio misrepresented his own position.

In posing the question on H1-B visas for tech workers, John Harwood contrasted Rubio, who has been eager to provide the tech industry more visas, with Senator Jeff Sessions. Harwood asked: “Your Senate colleague, Jeff Sessions of Alabama, says in reality, the tech industry uses this program to undercut hiring and wages for highly qualified Americans. Why is he wrong?“