Don’t get me wrong. This is a perfectly good essay about Donald Trump’s racism by Jonathan Chait. I just can’t imagine writing something like it myself anymore because there is no joy in going over the same things over and over again, and it’s insane to think it will be bring a different result. At this point, it just seems like serving the regular customer as the corner table of the diner the exact same breakfast he’s ordered for the last thirty years straight. Yes, I know he will eat it and come back tomorrow for more, but what’s really in it for me beyond that?

What’s more insightful is the piece Daily Kos Elections published on Sunday. Of particular interest is the map they created showing the predominant self-reported ancestry of every federal congressional district in the country. When you’re looking at it, keep in mind that this is just the “most-reported” country/region of origin, so it can be a majority or more often a simple plurality. For example, don’t conclude that over 50 percent of the people in House Intelligence Committee chairman Adam Schiff’s CA-28 district are Armenian.

Can you tell that Texas was annexed from Mexico in 1845 and that “California and a large area comprising roughly half of New Mexico, most of Arizona, Nevada, and Utah and Colorado” were ceded in 1848 with the Treaty of Guadalupe Hidalgo? Those areas (with the exception of Utah) are red today not only because of recent Mexican immigration, but because they were originally part of Mexico. How many tea bagger and Trumpistas are even aware of this?

Black of African-American is the most commonly reported ancestry in the South because of slavery. Some northern urban districts (like Baltimore) are plurality or majority black today because of the northern migration after the Civil War. Likewise, Irish-Americans predominate in New England, Germans in the northern Midwest, and Scots-Irish (who seem to call themselves “Americans”) in Appalachia because of 18th and 19th-Century immigration patterns.

Today’s America is a product of yesterday’s wars, immigration patterns, and laws about human bondage and civil rights. Virtually every congressional district on that map tells an unsurprising story if you know your American history. And, collectively, they show how initial settlers (like New England’s Protestant Congregationalists) were overwhelmed by later settlers (like potato-famine fleeing Irish-Catholics). You can see how the Mormons took over Utah, and how the Cherokees were driven out of the southeast and into Oklahoma.

All of these people are “real Americans.” In fact, most Americans today are a mix of several of these groups. I have ancestors who came over on the Mayflower and ancestors who arrived from Northern Italy and signed their name with an ‘X.” My mother’s maiden name is probably a misspelling of her great-grandfather’s home town.  I have German ancestors who settled the town of Berlin, Pennsylvania. If I had to estimate, I’d guess that I have more German ancestry than anything else, but I don’t even know that for certain. If I had to answer the question, I’d be tempted to just say “American.”

I’m as white as ghost because none of my forebears, as far as I am aware, came from anywhere south of the Italian Alps. Yet, I wouldn’t be shocked if a genetic biologist discovered I have a black or Mexican or Native-American ancestor. The history of America and the settlement of the West involved a lot of mixing of groups, much of which was never formally acknowledged in any government documents. This is as true of the black population as any other–perhaps more so. Only racial laws that discriminated against people who were as little as one-eighth black have kept us from recognizing that the black population is as genetically diverse as the white population.

President Trump thinks about genetics with the same degree of scientific literacy and rank prejudice as earlier 20th-Century anti-Semites and eugenicists. He’s an idiot.

But we knew that.

I don’t need to keep saying it.