By Cokie Roberts and Steven V. Roberts

Trumpian tirades against immigrants and refugees are part of a very American tradition. But they also violate this nation’s basic moral values and economic self-interest.

How can both be true? Easily. Trump is only the latest in a long line of nativist demagogues who periodically predict that the next wave of newcomers — Irish and Italians, Germans and Jews, Chinese and Japanese — will degrade and demean the American culture. History has proved them all wrong.

Each of those groups is a highly productive and patriotic part of American society today. History will prove Trump wrong, too, and we will look back on his demonization of Hispanics and Muslims as a dark stain on our national narrative.

Meanwhile, however, he’s doing a great deal of damage. Take the number of refugees the U.S. will admit in the next fiscal year. President Obama set the annual cap at 110,000; Trump slashed that number this year to 50,000, the lowest in 30 years, and next year the limit will drop again to 45,000, The Wall Street Journal reports.

Trump’s war on refugees is a disastrous mistake and a totally self-inflicted wound.

“Rather than making America great again,” editorialized the Washington Post, “it would do the very opposite by making the country small, peevish, inward-looking and heedless of its role on the global stage.”

One Trumpian trope is that refugees are costly to the country, a drain on public resources, so the president ordered a government study to prove his point. But the research showed exactly the opposite. Refugees — because they are often young, hard-working taxpayers — brought in $63 billion more in government revenue over the last 10 years than they cost in services.

The Ministry of Alternative Facts in the Trump White House was horrified and killed the report, according to The New York Times.

This is not just intellectually dishonest but economically self-defeating. All immigrants, including refugees, are a strong net plus for the economy, and that is especially true in the aging heartland that delivered Trump his victory.

A study by the Chicago Council on Global Affairs concludes that the Midwest depends “on immigration as an economic lifeline” to replenish departing young people and retiring baby boomers. As the study’s author told The Atlantic: “For the cities of the Midwest, restricting current immigration levels is the last thing they need.”

The second argument advanced by the anti-refugee crowd is protecting national security, but again, this is full of non-facts. Since 9/11, not a single American has been killed in a terrorist attack perpetrated by a refugee, and that’s because refugees are subjected to exhaustive scrutiny before they are allowed to resettle here.

Moreover, few refugees are young men of military age. Michael Chertoff, who was secretary of homeland security under President Bush 43, wrote in the Post: “Only the most vulnerable — those whose safety cannot be assured in their countries of first refuge — are selected for resettlement. For these refugees — widowed women; orphaned children; survivors of rape, torture and brutal religious persecution — refugee resettlement is a lifeline.”

The deepest damage inflicted by Trump’s refugee policy is to our national honor and reputation. How can we ask other national leaders to shoulder the burden of a worldwide refugee crisis — often at great political risk, as Angela Merkel has learned — if we slam our own doors?

The answer is we cannot. “We need to show our friends and allies that we stand with them and this is a shared burden,” says Chertoff.

The War on Refugees is part of a larger pattern, a deliberate and long-standing attempt by Trump to dredge up xenophobic impulses for his own political profit. The birther movement, the Mexican wall, the Muslim ban, the defense of neo-Nazis after Charlottesville, even his denunciation of black athletes who stand up or kneel down for racial justice — this is Trump at his race-baiting, fear-mongering worst, and two-thirds of Americans tell the latest ABC/Washington Post poll that he is dividing the country rather than uniting it.

“We’ve never had a president who so relishes producing animosity and hate among Americans, and who does it so consistently, so gleefully and so intentionally,” Peter Wehner, a former adviser to President Bush 43, told the New York Times.

The verdict of history is certain. This president dishonors the country and defaces the flag he professes to love so much. But the refugees he refuses to take in, the widows and orphans and survivors who truly do love the flag, will continue to suffer from his cruelty.

Steve and Cokie Roberts can be contacted by email at stevecokie@gmail.com.