Democrats have a border security problem. Yes, there is the immediate problem of the biggest migrant surge in 20 years that has left thousands of children in U.S. custody under questionable conditions with little transparency. Some 100,000 people attempted to enter the country in February alone, up from a little over 30,000 southwest border apprehensions the same time last year.

Surges happen for a variety of reasons, with one occurring in 2019 even under the harsh policies of Donald Trump. But Democrats have developed a squeamishness about immigration enforcement, except as a way of removing violent criminals in the way tax charges were used to finally get Al Capone.

Biden has proposed a moratorium on deportations. He has eased rules preventing new immigrants from relying on government services and ended Trump's requirement that asylum seekers stay out of the country while their applications are approved. He has introduced an immigration bill that would legalize millions of undocumented immigrants who are already here, including an eight-year pathway to citizenship, and is light on border security measures compared to similar proposals in the past.

While hesitant to use the word "crisis" to describe the situation at the border, the White House has acknowledged this is an enticement for people who might want to come. "Surges tend to respond to hope, and there was a significant hope for a more humane policy after four years of, you know, pent-up demand," Roberta Jacobson, the Biden administration's coordinator for the southern border, told reporters at a briefing last week. "So, I don't know whether I would call that a coincidence, but I certainly think that the idea that a more humane policy would be in place may have driven people to make that decision."

Our neighbors to the south agree. "They see him as the migrant president, and so many feel they're going to reach the United States," Mexican President Andres Manuel Lopez Obrador said of Biden at the beginning of the month.

Some of Biden's fellow Democrats go even further. Rep. Joaquin Castro of Texas, a rival for the presidential nomination and brother of the former secretary of housing and urban development, has proposed decriminalizing illegal border crossings. A significant faction of House Democrats would like to abolish Immigration and Customs Enforcement.

This isn't quite open borders. But it does suggest that it's difficult to enforce the border in a way that aligns with progressive sensibilities.

It wasn't always this way. Back when Biden's former boss Barack Obama was a freshman senator from Illinois, he said, "We simply cannot allow people to pour into the United States undetected, undocumented, unchecked, and circumventing the line of people who are waiting patiently, diligently, and lawfully to become immigrants in this country." As president, Obama believed that establishing credibility on enforcement was an important component of building support for immigration reforms that would legalize most of the undocumented population.

Hillary Clinton has at various points supported border fencing and opposed drivers licenses for undocumented immigrants, stances she later revised. As recently as 2018 she told The Guardian that "Europe needs to get a handle on migration" in order to counteract a rising tide of populism and nationalism.

The longtime liberal congresswoman from Texas who chaired Clinton's husband's immigration reform commission in the 1990s, Barbara Jordan, said that "deportation is crucial," something that would be anathema to progressive activists today.

"Credibility in immigration policy can be summed up in one sentence: those who should get in, get in; those who should be kept out, are kept out; and those who should not be here will be required to leave," Jordan said. "The top priorities for detention and removal, of course, are criminal aliens. But for the system to be credible, people actually have to be deported at the end of the process."

Some of the Democrats' leftward movement on immigration is a reaction to Trump. His "zero tolerance" policy led to the original "kids in cages" scandal. Whatever the merits of his critique of a permissive immigration policy, his way of speaking about immigrants themselves was often demeaning or worse. And much of what Democrats do these days is in response to Trump.

But when Obama sought to enforce immigration laws before Trump, progressive activists began calling him the "deporter-in-chief." When Bernie Sanders pointed out the unsettling effect open borders would have on U.S. labor markets and its welfare state, as well as the idea's libertarian pedigree, he faced liberal outrage.

We're not going to have open borders, of course. But today's liberals have a hard time enforcing immigration laws against poor people of color, even if the failure to do so consistently can encourage migrants to take extreme personal risks in situations where they are more likely to wind up in a detention center than the promised land. And they are unwilling to grapple with the impact huge numbers of low-paid immigrants have on the wages of working-class Americans who are themselves disproportionately Black and Latino.

This is Biden's first real test as president. But if Democrats don't start thinking more soberly about immigration, it won't be the last.