Donald Trump walked on stage at the Republican National Convention July 18 to Queen's "We Are the Champions." Trump was introducing his wife Melania who also addressed the crowd. (The Washington Post)

Danielle Allen is a political theorist at Harvard University and a contributing columnist for The Post.

When airplanes hit the twin towers nearly 15 years ago, not only our compatriots but also the complacent pleasures of our post-Cold War prosperity were snuffed out in the flames. We would have to defend ourselves. But would we be able to do so without sacrificing our core values, our civil liberties, our openness to the world and our philanthropic spirit? We entered an existential struggle not just with terrorists but also with ourselves. Tuesday night, with Donald Trump’s nomination for president, we learned that within a significant part of our country the terrorists have struck their mark.

Donald Trump, emerging from shadow, gives a thumbs-up sign as he walks on stage to introduce his wife, Melania Trump, Monday at the Republican National Convention in Cleveland. (Timothy A. Clary/Agence France-Presse via Getty Images)

The Republican Party has snuffed out its openness to the world and the philanthropic spirit it once claimed under the mantle of “compassionate conservatism.” Those conservatives who still adhere to those values, and to a steady and disinterested defense of civil liberties, are a party in exile. I raise my glass to you, for such attempts as you made to stave off defeat.

Now we must face the development of an isolationist party, open to labeling peacefully protesting fellow citizens as enemies, and ready to stoke an emotional maelstrom around narratives of betrayal in the pursuit of ends that remain obscure.

In its effort to develop the Trump campaign into a “movement,” this big brassy convention is trying to make the man more than he is. Following the script laid out in Trump surrogate Jeffrey Lord’s book “What America Needs: The Case for Trump,” the convention is giving us Trump the “Defender,” the “Truth-Teller,” the “Leader Who Can Get Things Done” and “Who Puts America First,” the “Rebuilder for the Republican Party” and the “Champion” — the silhouetted figure who entered to the relevant Queen song Monday. The only Trump we haven’t yet gotten from the table of contents of Lord’s book is Trump, the “Debt-Bomb Defuser.” Perhaps that role strikes too close to home given all the debt-bombs that have gone off in Trump’s life.

So that’s the script. Take note, so you can judge the contents of this convention for yourself.

Against the backdrop of these big themes, it may be the small moments that tell us more truly who Trump is. Here are a few.

Monday night, Trump made a World Wrestling Federation-style entrance to introduce his wife. He had the entire nation’s attention, perhaps for the first time. He didn’t have to speak for long, but he should have said something that mattered. It was the one-liner opportunity of a lifetime. What did he produce? “Oh, we’re gonna win. We’re gonna win so big. Thank you very much, everybody. Thank you. Thank you very much. We’re going to win so big. Thank you very much, ladies and gentlemen. We’re going to win so big. Thank you.” That’s it. A big fat serving of nothing. The grandiose buildup led nowhere but to ego affirmation. This is not the performance of generosity and humility we should seek from our best leaders.

Tuesday night, Donald Trump Jr. made the teeniest, tiniest of slips, in a speech written for him by Frank H. Buckley of George Mason University. We’ll hold Buckley responsible for what came off like a Freudian slip. Late in his speech, Trump Jr. proudly announced that his father would be a president “who speaks his mind and not just when it behooves him to do so.” I think Trump Jr. meant to suggest that his father doesn’t speak his mind merely when it is in his own interest to do so. But his actual words said something else.

During his speech at the RNC in Cleveland on July 19, Donald Trump Jr. discussed how education can lead to more opportunities for success, but that schools today are "stalled on the ground floor." (The Washington Post)

It behooves us to say things that it is our duty or obligation to say, and when they are timely, appropriate and fitting. In other words, those who speak when it behooves them to do so exercise good judgment. As Trump Jr. said, his father frequently errs in this judgment. His father is given to wildly irresponsible remarks and tweets. Judge Curiel come to mind, anyone?

In the smallest details, the truth will out.

Third, for the past few months, the coverage of the election has taken it as a truism that the Trump campaign is fueled by concerns about trade, immigration and national security. But this convention has upended my view of that. Pay attention to the relative amount of applause when trade themes are invoked as against the immigration and national security themes. The former doesn’t get much. It’s the latter two that turn out to be at the core of the response to Trump. We are indeed watching the long tail of Sept. 11.

Finally, there is how Lord ends his written defense of Trump. Trump, he argues, believes we are a country founded on “freedom and liberty.” Strangely enough, this echoes Paul Ryan’s interview Monday with the Wall Street Journal, when he explained how he could work with Trump. There are principles, he argued, and policies, and as long as the two agree on principles, they can disagree on policies and still work together. Then Ryan proceeded to tick off his core principles, counting on his fingers as he went. The first finger got, “Liberty, freedom, free enterprise, self-determination.” The second finger got, “Government by consent.” The third finger got “Constitution.” Ryan seemed to stop, and then he caught himself remembering a fourth principle. He tapped his fourth finger and said, “Upward mobility.”

Well, what’s wrong with those principles? Notice anything missing? I’m a lover of liberty, of free enterprise, of self-determination, of upward mobility, of government by consent, and of the Constitution. But I am also a lover of equality. “Liberty and freedom”? Turns out Trump and Ryan agree on that pleonasm. But that weird redundancy short-circuits the core of our political tradition. We are a country founded on the union of liberty and equality.

Skeptical? Don’t take it just from me. I know I’m always quoting the old guys, and here I go again. Take it from Lincoln. Liberty and equality belong together like hand and glove. As he put it: “Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.”

Yes, the party of Lincoln is dead. So to the party in exile, a name for your new party is waiting. May you now found the Lincoln Party. Then I will raise my glass to you again.