Ilhan Omar, Alexandra Ocasio-Cortez, Rashida Tlaib and Ayanna Pressley are four Democratic freshman members of Congress from safe urban seats. All have gotten crosswise of Speaker of the House Nancy Pelosi because they have an appetite for publicity that is not traditionally tolerated in freshmen, and because some of their ideas look disconcerting to the kind of middle class suburban voters in swing districts who gave the Democrats a majority of the House in 2018 and whose support the party may need in 2020. A Democrat who doesn't agree with them might consider the four to be presumptuous, provincial and naïve, or even worse, but that's normal intra-party squabbling.

President Donald Trump decided he could use this quarrel among the opposition to make a broader point about who deserves to speak and be heard in this country. Over last weekend, he tweeted that the four women should “go back and help fix the totally broken and crime infested places from which they came.” When that tweet drew widespread criticism as racist and nativist, the president doubled down and called the four women enemies of the United States who should apologize to him and to the country. After the crowd at his latest rally chanted “Send Her Back” at the mention of Omar's name, the president tweeted that they were “great people.”

As has been pointed out, only one of the four women is foreign-born. Omar is a Muslim Somali born in Africa. Tlaib is the American-born child of Palestinian immigrants. Ocasio-Cortez is also a birthright citizen, born in the Bronx of birthright citizens from Puerto Rico. Pressley is an African-American, whose family has almost certainly been in this country longer than the president's immigrant grandfather. But why let facts get in the way of a good tweet? Perhaps the president believes that Detroit, the Bronx and Boston are foreign countries or might just as well be. Or perhaps “go back” just means “shut up and disappear.”

The president, his official spokesmen and unofficial cheerleaders, and his supporters, vehemently deny that his remarks are racist. They can say this with a straight face because they make racist assumptions that are so deeply embedded in American history that they are taken for granted. In Dred Scott v. Sandford (1857), Chief Justice Roger Taney stated flatly that the Declaration of Independence did not mean what it said about all men being created equal and that the Founders really understood that the United States and its Constitution were created of, by and for white men alone. After the bloodiest war in our history, the Citizenship and Equal Protection Clauses of the Fourteenth Amendment overruled Dred Scott. All people born or naturalized in this country are by law citizens on an equal footing, and the newest among them has as much right to criticize this country as Mayflower descendants.

The president is the country's chief law enforcement officer, with the constitutional duty to “take care that the laws be faithfully executed.” When he says in effect that these four Congresswomen don't belong here and aren't real Americans, he assaults public confidence that he will enforce the law fairly and equally. He can do it because Taney's ghost still walks among us.

The United States was founded by English-speaking white men, and its language, its laws and its culture derived from England. This history leads all too many white Americans to assume that English-speaking white men are the American norm, that anyone else must earn the right to be American, that they can earn that right only by assimilating to the conduct and values of English speaking white men, and that the true Americans retain the right to judge whether outsiders have conformed enough to measure up to the standard for acceptance.

This presumed right of judgment has been applied by American nativists successively to the Irish, the Germans, the Italians, the Slavs and the Jews, all of whom have been told at various times to go back where they came from.  As each wave of white immigrants has been conceded true American status after nativist hazing, they have in turn assumed the right to judge the next wave as if their own ancestors had come ashore on Plymouth Rock. Like Taney, they apply this right of judgment reflexively to African-Americans—whose ancestors have been here longer than many of them—and to anyone not European by descent or Christian by religion. The president is now applying it to a Muslim immigrant from Africa and three native-born women of color.

This, our nativists will tell you, is not racism but historical fact, and their birthright as Americans is to decide who deserves to share in the precious inheritance handed down to them by the Pilgrims, the Founders, the Pioneers and the Greatest Generation. Well, that precious heritage has two parts. One is Jefferson's universalist ideal in the Declaration of Independence. The second is the reality of the slave labor that paid for Jefferson's income. While we don't like to talk about it much, the history of the United States is deeply racist. Every foot of ground we stand on was taken from the original natives at gunpoint by Euro-Americans who assumed they had the right to dispossess the people they called savages because they were building a higher civilization. Our industrial revolution was paid for in large part with capital earned or borrowed on the export of cash crops grown by black slaves and sharecroppers. Asian immigrants were excluded and forbidden to own land, and even Asian citizens were rounded up and sent to concentration camps because they were Asian. African-Americans and Latinos were unashamedly deprived of real citizenship by law and by extralegal violence until well after the Second World War. Our immigration laws from 1920 until 1965 were expressly designed to keep American not only white but Nordic.

Until about 50 years ago, our constant and sometimes strident invocation of Jefferson's ideals of equality always came with a quiet whisper of Taney's “for white men only.” Everybody else got as much freedom and dignity as white men were graciously pleased to allow them. It wasn't until after the defeat of Hitler by our segregated military that large numbers of white Americans began to reflect honestly on the fact that we had a master race in this country and to try to make the Declaration of Independence and the Fourteenth Amendment really mean what they said for everyone, and not just for white men.

We have abolished Jim Crow in law, but Chief Justice Taney's assumptions about who is really American live on in the mind of the president and those who chant “Send Her Back.” Until we recognize that fact about ourselves and root it out of our hearts and minds, Lincoln's attack on the anti-immigrant Know Nothing party will remain true. “As a nation,” Lincoln wrote, “we began by declaring that 'all men are created equal.' We now practically read it 'all men are created equal, except negroes.' When the Know-Nothings get control, it will read 'all men are created equal, except negroes, and foreigners, and Catholics.' When it comes to this I should prefer emigrating to some country where they make no pretense of loving liberty—to Russia, for instance, where despotism can be taken pure, and without the base alloy of hypocrisy.”