It is a sign of the times that immigration has not been mentioned in three hours of debate between the presidential tickets. A review of the transcripts of both the presidential and vice-presidential encounters finds no questions asked nor answers proffered about an issue that until only recently defined much of our politics and distinguished our two parties. Needless to say, both moderators wanted to know where the candidates stand on climate change, which routinely drifts toward the bottom of any list of public priorities.

Why the omission? It is tempting to say that immigration did not come up because the elites who manage the presidential debates are uncomfortable with the topic, are worried that the issue favors Republican border hawks, and are more interested in subjects relevant to their cultural coterie. But it is also true that presidential debates tend to focus on current events and pressing challenges, and that immigration just does not seem as great a concern today as the coronavirus, the economy, race relations and civil unrest, and California brushfires.

The apparent irrelevance of immigration and border security to the election might also be attributed to the achievements of the Trump administration. But these achievements are partial, tenuous, and dependent on events and relationships and court decisions. And they are easily reversed. What should worry the president is that the somnolence on the border deprives him of the very issue that propelled his rise to power, and that drove the populist revolt against the Washington establishment whose offshoots included the Ron Paul candidacies, the Tea Party, and Republican victories in 2014 and 2016. Immigration is next only to the economy and to the courts as a place where the president can contrast his record and agenda with Biden’s and appeal to national solidarity and historical tradition. His parlous electoral status may be related to the fact that immigration is not much of a factor in this most unusual campaign.

There is no gainsaying immigration’s importance to the Trump presidency. It was immigration that triggered the grassroots rebellion against the George W. Bush and Barack Obama administrations, and against congressional supporters of amnesty for illegal immigrants, culminating in Trump’s 2016 primary victory. Immigration became the touchstone of Trump’s campaign on day one and served as the cudgel by which he defeated Jeb Bush and other Republicans for whom the Bush-Obama approach to legalization was correct. The border wall was not only a rallying cry but also a symbol of how a Trump presidency would privilege American citizens above all else. And Trump fused immigration to economics, by opposing H-1B visas; to crime, by highlighting gang activity; and to national security, by enacting his travel ban against countries that sponsor terrorism.

When Kamala Harris offhandedly mentioned the travel ban during the vice-presidential debate, it almost seemed like an anachronism, so far removed are we from the world of January 2017. The coronavirus imposed its own sort of prohibition. It radically interrupted the mechanisms of globalization, including the flow of labor. Global air travel plunged, and so did apprehensions along the southwest border. The virus ushered in a condition of emergency, in which the Trump administration tightened visa and asylum procedures.

The pandemic accelerated an ongoing trend. The growth in the illegal immigrant population appears to have stopped abruptly during the 2008 global financial crisis and has trended slightly downward since. The composition of that population has also changed, from able-bodied men seeking work to women, children, and the impaired fleeing gangs and state collapse. Border crossers are less likely to be Mexican and more likely to be from Central America or Asia. The Trump administration’s wide-ranging actions, in particular its Migration Protection Protocols, further discouraged unauthorized entry. By 2019, according to the Brookings Institution, the net increase of immigrants in the U.S. population was at its lowest level in years. (And, it might be added, the best job market in half a century was producing income gains across the population.) There is every reason to expect that the combined effects of the pandemic, the lockdowns, and executive orders will keep the number of migrants low.

But for how long? Harris attacked Trump for his “Muslim ban,” but she did not say on stage what the Biden administration would do about it. For answers, one has to turn to the Biden-Harris campaign website. There, the Democrats write that they would “rescind the un-American travel and refugee bans, also referred to as ‘Muslim bans.’” They would “end Trump’s detrimental asylum policies,” including the Migrant Protection Protocols. They would reverse the public charge rule, which makes it harder for welfare beneficiaries to become permanent residents. They would halt construction of the border wall and “direct federal resources to smart border enforcement efforts, like investments in improving screening infrastructure at our ports of entry.” They would reinstate the DACA protections for illegal immigrants brought here as children, and for their parents. And Biden and Harris would “create a roadmap to citizenship,” not permanent legal residency, for the remaining millions of illegal immigrants “who register, are up-to-date on their taxes, and pass a background check.”

In short, a President Biden would return immigration policy to the status quo before Trump. With this difference: Biden, unlike Obama, would be dealing with a Democratic Party whose left wing has been radicalized and includes prominent officials who support such extreme measures as decriminalizing border crossing and abolishing U.S. Immigration and Customs Enforcement. Senator Harris herself has called for “restructuring” ICE (and for abolishing private health insurance, banning fracking, and imposing universal background checks for gun purchases through administrative fiat). The leftward drift of the Democrats makes immigration politics more fraught, and more polarizing. Having learned nothing from the Trump phenomenon, Biden and Harris are eager to reinstate the exact policies that gave birth to it.

The failure to control the border and to think politically, rather than economically, about immigration was part of a larger failure. Republican and Democratic elites neither recognized nor acknowledged that the globalized world of the 21st century, while beneficial to them, carried costs for large parts of the population far greater than they had assumed. It is therefore ironic that a pandemic originating in China, which America treated for too long as a “responsible stakeholder” rather than a revisionist great power, has overwhelmed practically every issue but the economy in the final month of the election.

If the Trump campaign fails to raise the question of immigration, the Democratic establishment that stands to gain from the public’s judgment of the president’s coronavirus response will happily ignore it. But they will not be able to avoid immigration forever. Or the furies it unleashes.

Matthew Continetti is a resident fellow at the American Enterprise Institute and the founding editor of The Washington Free Beacon. For more from The Washington Free Beacon, sign up free of charge for the Morning Beacon email.