Lately, blows have been dealt to the conventional wisdom surrounding billionaire and Republican presidential candidate Donald Trump.

First, the smart money told us that Trump just enjoyed all the media attention a potential White House run brought his way, that he would never actually become a real candidate.

Then after Trump’s rambling announcement speech on June 16, the smart money had a fresh analysis: All this media coverage, the savvy Donald shrewdly calculated, was just more free publicity to boost the ratings of his TV shows and to burnish the Trump brand.

Wrong. In the first three weeks following his formal entry into the 2016 race (that’s when he infamously stereotyped Mexicans who immigrate to the United States: “They’re bringing drugs, they’re bringing crime. They’re rapists and some, I assume, are good people”), both Univision and NBC told Trump that because of those remarks the Miss USA pageant, which he partly owns, would be knocked off the air.

Then Macy’s, apparently having taken more than two weeks to read the transcript, announced that it was “disappointed and distressed by recent remarks about immigrants from Mexico” and would no longer sell Trump’s line of clothing.

This campaign, up to now, has been nothing but damaging to the Trump name and bottom line.

Still, let us be fair to Trump. Offensive, stupid and hateful as his words may be, he sounds an anti-immigrant theme that has a long and ugly tradition in American politics.

In the middle of the 19th century, when Catholics from famine-plagued Ireland and Germany came to this then-overwhelmingly Protestant country, they encountered suspicion, bigotry and violence. It was President John Adams who earlier had written, “A free government and the Roman Catholic religion can never exist together in any nation or country.”

Catholic churches and convents were burned in Boston and Philadelphia. The nativist American, or “Know Nothing,” party in 1854 won smashing election victories in Delaware, Kentucky, Maryland and New England, especially Massachusetts, where the Know-Nothings won every statewide office, including the governorship and both houses of the Legislature. Seventy-five members of Congress won on the anti-Catholic, anti-immigrant ticket.

Italian immigrants were even more unwelcome when they arrived later in the 19th century. So, too, were arrivals from elsewhere in eastern and southern Europe. Working-class and lower-class Americans felt threatened economically by the newcomers. But, beginning around the turn of the century, the intolerance leveled against Jews from Poland and Russia was especially brutal.

By 1920, bigots, many of whom were well educated and socially prominent, could quote the report from a State Department office that categorized the 120,000 Jews who had entered the country as “twisted,” “​unassimilable,” “filthy” and “un-American.” By then, the American Legion opposed all immigration to the United States, purportedly because it was the “source of radicalism.”

We now know how wrong all those loud voices of exclusion were. We know and cherish the magnificent tapestry all the people from everywhere have created in these United States.

Let us honor those who dared to stand up for the oppressed outsiders, these scared newcomers who dared to travel across the ocean or the continent to a place they had never been, to live among people they had never met, to speak a language, in many cases, they had never heard.

Donald Trump, please meet America.

Mark Shields is one of the most widely recognized political commentators in the United States. The former Washington Post editorial columnist appears regularly on CNN, on public television and on radio. Click here to contact him, or click here to read previous columns. The opinions expressed are his own.