Those whose life’s mission is resistance to Trump were encouraged by George W. Bush’s recent jabs at the president. Bush was primarily concerned about defending his administration’s foreign policy, and while Trump-haters also despised Bush back then, Trump is today’s enemy and it seems that my enemy’s enemy is my friend.

What was more interesting in Bush’s speech was what he had to say about nationalism. Trump-haters struggle to understand just what happened in last year’s election, but as the mist clears it’s become apparent that we’re witnessing the rise of a new conservatism that is explicitly nationalist.

And because of this, it becomes important to distinguish between the different forms nationalism might take, good and bad. For that reason, Bush’s speech deserves our attention.

Here’s what he said: “Our identity as a nation . . . is not determined by geography or ethnicity, by soil or blood. Being an American involves the embrace of high ideals and civic responsibility. We become the heirs of Thomas Jefferson by accepting the ideal of human dignity found in the Declaration of Independence.”

That’s exactly what Abraham Lincoln said in 1858. What makes us Americans is our allegiance to a creed. This also excludes some noxious forms of nationalism, such as the white nationalism that Bush denounced in his speech.

Mind you, attacking white nationalists doesn’t take much guts. As a profile in courage, that’s at the same level as saying you’re not quite sure that Harvey Weinstein is a great role model.

I’d be more impressed if a politician went out of his way to denounce the trouble-makers on the left as well as the right. You know, as Trump has done. Richard Spencer, Antifa — is there any reason to choose between them?

There’s another kind of debased nationalism that also deserves condemnation, though Bush didn’t mention it. It’s the cultural nationalism that’s a mask for white nationalism, a nationalism employed not to unite all Americans but to divide and exclude some of us. But if you look more carefully at what constitutes true American culture, it doesn’t leave much room for white nationalism.

The cultural nationalist is right to say that being an American is more than subscribing to the principles of the Declaration. A lot of people in other countries embrace those ideals, and they’re not American. Becoming an American requires a few more things: American citizenship, and a love for American institutions that aren’t owned by a single race.

You can be an American if you don’t like baseball and apple pie. You can be an American if you don’t like Scott Joplin and chili dogs. You can be an American if you don’t enjoy Louis Armstrong and Selena. It’s just that you might be a wee bit more American if you did so. There is an American culture.

But it’s not a white culture or a black culture or a Mexican culture. That’s why the American who sincerely hates multiculturalism is something less than an American.

That’s how W.E.B. DuBois saw it. “I sit with Shakespeare, and he winces not. Across the color line I move arm and arm with Balzac and Dumas, where smiling men and welcoming women glide in gilded halls.” That’s how we’d want it, but when the only culture that counts is a white American one, that’s inconsistent with American nationalism.

There’s another kind of ideology that’s inconsistent with nationalism, and you’ll see it in the person who doesn’t prefer Americans to non-Americans. This might be the leftist who thinks half the country is deplorable. Or the Republican who distinguishes between “makers” and “takers.”

There’s a logic to nationalism that demands an affection for fellow citizens of every kind, and that asks us to look out for the less fortunate amongst us. The pure libertarian who doesn’t think his government owes anything to fellow citizens in distress might be faithful to his right-wing ideals, but he’s not much of a nationalist. Along with Jefferson’s liberty and equality, nationalism also embraces an ideal of fraternity.

That’s why, until now, a right-wing Republican Party has been hostile to nationalism. And why Trump’s national conservatism represents a rejection of the Republican establishment.

There’s something new in the air. It is something that John Adams and Franklin Roosevelt, Abraham Lincoln and John F. Kennedy understood. It is what nationalism demands of us.

F.H. Buckley teaches at Scalia Law School.