Who said this? “If you don’t have any borders, you don’t have a nation.” The speaker went on, “Trump did a better job. I don’t like Trump, but we should have a secure border. It ain’t that hard to do. Biden didn’t do it.”

It was Sen. Bernie Sanders, I-Vt., in characteristic candor. If, as Milton Friedman argued, you can’t have open borders and a generous welfare state, Sanders, as a self-described socialist, prefers the welfare state.

The facts at this point are not in much doubt. The Pew Research Institute, not an anti-immigration outfit, estimated that there were 10.2 million “unauthorized” immigrants (members of groups not approved for legal immigration) in the United States in 2019, the year before former President Joe Biden was elected, and 10.5 million in 2021, the year he took office.

That number, as Pew’s Jeffrey Passel and Jens Manuel Krogstad wrote, grew to 14 million in 2023, “the largest two-year increase in more than 30 years of our estimates.”

Pew estimated that the illegal immigration population increased from 3.5 million in 1990 to a peak of 12.2 million in 2007-08, the years housing prices and financial markets crashed. Suddenly, net migration from Mexico turned negative, and the illegal population fell through attrition until Biden took office. Then it rose from 10.5 to 14.5 million.

That number has trended down since President Donald Trump took office last January.

This provides some backing for the Trump Department of Homeland Security’s claim that it removed 527,000 illegal immigrants and that 1.6 million “have voluntarily self-deported.” That’s obviously an estimate, but it’s not improbable.

If some of the moral opprobrium for the harm done belongs to the Trump administration for arguably enforcing the law too vigorously, some moral opprobrium is owed also to the Biden administration, which deliberately refused to enforce the law in a way that left millions of people vulnerable to severe disruption.

My guess is that the current policy will disincentivize illegal immigration long after Trump, as he has conceded this week, leaves office in January 2029. Who will want to make long-term plans that can be ruined by sudden deportation or hurried self-deportation?

Much of the drama around the Trump administration’s enforcement of the law comes from opposition, sometimes forcible, of Democratic governors and mayors who promised, in the tradition of John C. Calhoun, to nullify federal law within their jurisdictions.

In his 2020 campaign, Biden did not promise to reverse a dozen years of policy and welcome in 4 million unauthorized immigrants. He did not argue that every person in the world has a right to move to the U.S. Yet he did those things, and most elected Democrats continue to support them.

“Immigration is a blind spot where Democrats focus first on the needs of migrants rather than the needs of Americans,” Democratic analyst Josh Barro wrote. Democrats need to “firmly say ‘no’ and deny access to our country, even to people who stand to gain a lot by coming here — and part of saying ‘no’ requires having an effective government apparatus.”

Instead, blue-state Democrats seem stuck in denial. They point to polls showing less insistence on reducing illegal immigration without realizing that, as Republican pollster Patrick Ruffini pointed out, “that may have something to do with the fact that illegal border crossings have plummeted to 0.”

As for dismay at Trump administration enforcement tactics, that’s real, but, as Ruffini noted, voters of all education levels prefer “a party that’s better at getting things done, even if its views are sometimes extreme.”

This gets back, doesn’t it, to Sanders’s words: “If you don’t have any borders, you don’t have a nation.”