When Donald Trump announced this week that he intended to sign an order temporarily halting all immigration to the United States, nativists and xenophobes cheered. The white nationalist group VDARE, for example, promptly proclaimed it would “never stop giving President Trump credit for this moment,” and regretted only that the ban hadn’t been announced on his first day in office. There was joy in MAGA Nation, too. When Charlie Kirk, a prominent 26-year-old pro-Trump activist, urged his Twitter followers to show they “are THRILLED Trump is suspending all immigration to the United States,” almost 36,000 of them retweeted the message.

But it would be a mistake to think that Trump’s latest move to keep immigrants out will find favor only within his hard-right base. Anti-immigrant sentiment has been growing since the coronavirus catastrophe erupted. Two nationwide Ipsos/USA Today polls in the past two months show surging support for stopping all immigration. As of April 13, when the second poll was released, that support had reached 79 percent.

Anti-immigrant animus has been a mainstay of Trump’s political career literally from Day 1: He launched his first presidential campaign with a speech that smeared Mexican immigrants as “rapists” who are “bringing crime” across the border. While such rhetoric elated some voters, it repelled many others. But now, with the nation reeling from a pandemic that has killed more than 50,000 Americans and cost 26 million their jobs, it is easier than ever to scapegoat immigrants. And Trump knows it.

Slashing immigration has been the president’s panacea for just whatever malady of the day catches his fancy — violent crime, terrorism, welfare dependence, the country being “full” — so it was pretty much a foregone conclusion that he would find a way to exploit the current crisis for the same purpose. The danger is that now, in a time of suddenly widespread fear and economic anxiety, a lot of well-intended voters might be misled into thinking an immigration ban is a prudent measure to protect the nation’s health and what remains of its jobs.

Which is what the White House wants voters to think.

“President Trump is committed to protecting the health and economic well-being of American citizens as we face unprecedented times,” press secretary Kayleigh McEnany declared in a statement on Tuesday. She quoted Trump as saying that “decades of record immigration have produced lower wages and higher unemployment for our citizens, especially for African-American and Latino workers.”

But barring immigrants is neither a sensible health precaution nor a way to reduce unemployment.

For starters, there is no connection between immigrants and coronavirus infections — the disease has erupted with equal severity both where the immigrant population is disproportionately high and disproportionately low. Massachusetts, a COVID-19 hotspot, was initially exposed to the virus, as Governor Charlie Baker noted the other day, not by immigrants but by business travelers attending a Boston conference hosted by the drug company Biogen.

On the other hand, America’s ability to successfully fight the epidemic is tied to immigration. As the Cato Institute’s David Bier points out, immigrants are heavily concentrated in frontline professions. Though immigrants are less than 14 percent of America’s population, they account for more than 28 percent of physicians, 35 percent of home health aides, 21 percent of nursing assistants, and 18.5 percent of clinical lab technicians. So dependent is the United States on foreign-born doctors and nurses in this emergency, in fact, that just last month US Secretary of Health and Human Services Alex Azar urged governors to waive state regulations that were keeping foreign-born medical personnel on the sidelines.

Nor is it true that more immigration equals more unemployment. Just look at the last 10 years: Between 2009 and 2019, the share of US workers born abroad skyrocketed — yet the economy boomed. The jobless rate fell to an incredible 3.5 percent. Tens of thousands of immigrants launched businesses that put hundreds of thousands of people to work. Unemployment among minority groups dropped to record lows.

Robust immigration made America healthier and wealthier in the past, and it will do so in the future — as long as Americans aren’t hoodwinked by cynical politicians into slamming the gates shut.

Trump’s latest anti-immigrant blast is pandemic politics at its most cynical. He claims to be “pausing immigration,” yet immigration is already paused. International travel has dwindled to a trickle. The State Department more than a month ago temporarily suspended routine visa services at all US embassies and consulates. And Trump’s executive order, signed Wednesday, is replete with exemptions. It doesn’t revoke any immigrant visas already issued. It doesn’t apply to any “healthcare professional.” It doesn’t affect EB-5 visas, which are issued to immigrants planning to invest significant sums in a US business venture. It doesn’t apply to foreign children being adopted by US parents. And it doesn’t apply to any immigrant whose entry the administration determines “would be in the national interest.”

Yet make no mistake: Trump is as hostile to immigration as he has ever been. His new directive doesn’t actually change any policy, but that isn’t its purpose. With the presidential election just six months away, Trump is stoking the nativism that galvanized his followers four years ago and helped him win the White House. This year, amid a spreading disease and economic wreckage, his immigrant-bashing may prove even more effective. That would be calamitous. America will win its battle against the virus, and likely sooner than later. But if we succumb to the anti-immigrant contagion, we will have sickened this nation for years to come.

(Jeff Jacoby is a columnist for The Boston Globe).