No State of the Union response speech has ever been a truly great speech, but Rep. Joe Kennedy III (D-MA) delivered what’s probably the best entry in the genre that I’ve ever heard Tuesday night.

I couldn’t put my finger on exactly what I liked best about it until I read an anonymous Republican snarking about it.

A GOP source texts: "As a Republican I love how at the end of the day, after all their years of crap about identity politics...Democrats picked a white dude from one of the most privileged families in America to do the response." — Jonathan Swan (@jonathanvswan) January 31, 2018

Kennedy’s speech was about how Americans are all in it together and should reject the false choices and inherent elitism of Donald Trump’s divisive politics.

Because here’s the thing — what liberals do in America, at their best, is not identity politics at all. Identity politics is what Donald Trump does. Identity politics is delivering a speech that offers no solutions for any actual problems in people’s lives, interspersed with dog-whistles about MS-13 and standing for the national anthem.

Republicans understand the remorseless mathematical logic of having a white guy stand up and deliver a speech about how whiteness is the best and then wrap it up with a bunch of white members of Congress lustily chanting “USA!”

The progressive counter, as delivered by Kennedy Tuesday night and by many other orators over the past 250 years or so, is that America is about equality.

“This administration isn’t just targeting the laws that protect us,” Kennedy said. “They’re targeting the very idea that we are all worthy of protection. For them, dignity isn’t something you’re born with, but something you measure by your net worth, your celebrity, your headlines, your crowd size.”

Then he slipped into the identity issues, calling out specific reasons Trump might slot you into something other than first-class citizenship. Wrapping up, he said: “Their record is rebuke to our highest American ideal, the belief that we are all worthy, that we are all equal, that we all count in the eyes of our law and our leaders, our god, and our government. That is the American promise.”

Abraham Lincoln, writing in 1855 about the anti-immigrant movement of his day, struck a similar tone:

Our progress in degeneracy appears to me to be pretty rapid. As a nation, 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 pretence of loving liberty -- to Russia, for instance, where despotism can be taken pure, and without the base alloy of hypocricy.

More recently, Barack Obama launched his political stardom with the argument that “there’s not a black America and white America and Latino America and Asian America; there’s the United States of America.”

He referred to “the hope of slaves sitting around a fire singing freedom songs; the hope of immigrants setting out for distant shores; the hope of a young naval lieutenant bravely patrolling the Mekong Delta; the hope of a millworker’s son who dares to defy the odds; the hope of a skinny kid with a funny name who believes that America has a place for him, too.”

I don’t know that Kennedy will run for president or whether if he did he’d be a good candidate or a good president. But he did give a good speech, precisely because he, like Obama and Lincoln before him, refused to be baited by the Donald Trumps of the world into accepting a vision of a segmented America.

Trump’s game is to pit people against each other and get them so caught up in their internecine games that they don’t notice the wholesale looting of America that’s taking place under his administration.

It will, in fact, probably be easier for black and Latino politicians to make this argument than for white Democrats, who can sometimes struggle with trying to convey the fundamental unity of American interests without scanting the significance of particular identities.

Kennedy is surely no more unaware of the broad irony of his ideals than any of the other privileged Kennedy politicians across the past three generations. But he just went for it. The speech was a good idea, and it worked.

GOP sources are texting snark about it, because the honest truth is they have no idea how to appeal to a diverse electorate.