Editor's Note: (Michael D'Antonio is the author of the new book, "The Truth About Trump." The opinions expressed in this commentary are his.)
(CNN) Every few days Donald Trump challenges us with his obsession with race, ethnicity, religion and gender and with his relentless effort to alienate us from each other.
The latest example finds him telling the Wall Street Journal that the federal judge hearing the fraud complaints against his defunct Trump "University" should disqualify himself because he is of Mexican descent. "I'm building a wall," said Trump, referring to his call for a huge border wall between the U.S. and Mexico, so the judge has "an inherent conflict of interest."
Trump defended the comments in an interview with CNN's Jake Tapper on Friday, saying: "He's proud of his heritage. I respect him for that," yet adding, "He's a Mexican." In fact, the judge was born in the U.S.
House Speaker Paul Ryan, who only Thursday said he would vote for his fellow Republican Trump, quickly criticized the statement about Judge Gonzalo Curiel, saying, " I completely disagree with the thinking behind that."
Ryan told WISN radio in Milwaukee, "... he clearly says and does things I don't agree with and I've had to speak up on time to time when that has occurred and I'll continue to do that if that's necessary -- I hope it's not."
Trump's claim about Judge Curiel shows he doesn't understand the first thing about the judicial system, which is based on the integrity of men and women who are charged with keeping their emotions and personal feelings out of their work on the bench.
Even more importantly, Trump's statement is just one of many he has uttered during the presidential campaign, and throughout his life, that reveal a warped perspective on what it means to be a citizen of a diverse country where differences are respected and valued.
It is, of course, only human for us to feel anxiety about people who may be different from us. The tendency to categorize others is a well-established element of human nature. But it is also human to seek to work against our prejudices and to understand that others always deserve respect.
We don't try to turn our negative assumptions into applause lines, or, as Trump did Friday, seek to exploit the racial identities of those we encounter. Trump did this at a campaign rally when he noticed a black man in the crowd and said, into the microphone, "Oh, look at my African American over there. Are you the greatest?"
For at least four decades, Trump has aired rather strange views about heritage and identity. As a young man, he repeated his father Fred's false claim that the Trump family -- the name was once Drumpf -- emigrated from Sweden, and not Germany. The senior Trump began calling himself Swedish after World War II because, as Donald Trump told me, he didn't want Jewish New Yorkers to connect him with the Nazi regime and take their business elsewhere.
This assumption, which Donald agreed with, betrays an exceedingly dim view of human nature. The Trumps expected bigotry from Jewish New Yorkers and they were willing to turn their backs on their ancestors to make money.
As Donald Trump moved through his adult life, he has regularly demonstrated an extraordinary level of concern about the ethnic and racial identity of people he encountered. When he testified before a committee in Congress about competing casino operators from Native American tribes he complained, out loud, that they "don't look like Indians to me."
In his book about Trump's years as a casino operator in Atlantic City, former Trump executive John R. O'Donnell wrote of how his boss made bigoted statements about African-Americans and Jews. O'Donnell quoted Trump saying:
"Black guys counting my money! I hate it. The only kind of people I want counting my money are short guys wearing yarmulkes... Those are the only kind of people I want counting my money. Nobody else ... Besides that, I tell you something else. I think that's guy's lazy. And it's probably not his fault because laziness is a trait in blacks."
Trump has both confirmed and denied the accuracy of O'Donnell's reporting. In May 1997, he told Playboy writer Mark Bowden about the book generally, "The stuff O'Donnell wrote about me is probably true." Two years later, when he was eying a third party run for president he told Tim Russert, "I've never said anything like it."
Prior to Trump's involvement in gambling, his real estate organization was subject to a crackdown by the U.S. government for failing to comply with fair housing laws governing applications for apartments by minorities. Trump answered with a countersuit in which his lawyer likened the feds to the "Gestapo" and "storm troopers."
The countersuit was dismissed by the judge in the case. In the end, Trump settled the case by agreeing to comply with the law and without admitting wrongdoing.
In 1989, he was back in the press again, telling Bryant Gumbel that, "A well-educated black has a tremendous advantage over a well-educated white in terms of the job market."
Foreigners have also come in for Trump's prejudice on a regular basis. In the 1980s it was the Japanese who secretly "laugh like hell" after completing unfair business deals Now it's the Chinese, whom Trump mocks by speaking broken English, but also offers as the wily, if not sneaky, bargainers who take advantage of America.
For much of President Obama's presidency ,Trump has led the so-called "birther" movement, alleging, in ridiculous defiance of all evidence, that Obama was born outside the U.S. and may not be a real American citizen. This campaign, which he pursued long after others dropped it, was clearly an attempt to turn the first African-American president into a foreign "other" and thus, presumably, render him illegitimate.
When the comedian Jon Stewart went after him on his satirical nightly broadcast, Trump reached once again for an argument based on ethnicity. He tweeted: "If Jon Stewart is so above it all & legit, why did he change his name from Jonathan Leibowitz. He should be proud of his heritage!" This from a German-American man who had posed as Swedish.
Trump started off his run for the presidency a year ago with a bigoted rant about undocumented Mexicans, braying about how "they're bring drugs, they're bringing crime. They're rapists." The effect of this talk was to ramp up public anxieties about people who are actually less likely to commit crimes than others. A pair of Massachusetts men were arrested for beating a Latino person they encountered on the street and, according to police, said, "Donald Trump was right."
Next Trump retweeted false "data" alleging that black assailants account for more than 80% of white deaths due to homicide. The numbers were too high by a factor of five. And don't forget Donald Trump's attitudes about the 1.5 billion Muslims of this world. Those who are abroad would be temporarily barred from our shores, on account of their religious faith, by a President Trump.
Now we have Trump's ethnic-based bashing of Gonzalo Curiel, which began with the suggestion that the judge, who was born in Indiana, was a Mexican man who somehow managed to become a federal judge.
When Trump appeared Thursday at a rally in San Jose, a peaceful protest outside turned violent. Eggs and bottles were thrown at Trump supporters and police made arrests. Some protesters waved Mexican flags. The words "Go back to Mexico," were shouted.
The beating in Massachusetts; the violence in San Jose; this is what comes from Trump's repeated effort to demonize others and pit one group of Americans against another.
Although his divisive view has gained more notice of late, it is not new. Indeed, it is a deeply felt belief that he has passed on to the younger generation of Trumps. His eldest son Donald Jr. told me that, "Like him [Donald Sr.], I'm a big believer in race-horse theory. He's an incredibly accomplished guy, my mother's incredibly accomplished, she's an Olympian, so I'd like to believe genetically I'm predisposed to better-than-average."
In Trump's world, comments about a person's ethnic and racial background are fair game. And yet he says, "I am the least racist person you have ever met."
Trump's kind of thinking was common in the 1950s, when he was a boy. This is the period evoked when he says he wants to "Make America Great Again." In fact, the 1950s were marred in many ways, including by the stereotypes people clung to about group identity.
Thankfully, most Americans grew beyond this type of thinking and learned to consider people as individuals and view character as paramount. What's most worrying about Trump is the evidence that he has not joined the rest of us.
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