The relationship between ideas and reality can be a funny thing.

On Monday, on the first full day of the Edmund Burke Foundation's inaugural National Conservatism Conference in Washington, D.C., ballrooms full of right-of-center intellectuals and journalists heard a stream of thoughtful and impassioned speakers defend a high-minded idea of nationalism just a couple of miles from a White House where, just one day previously, a self-described nationalist president spewed xenophobic bigotry at a handful of his congressional critics.

It was hardly the only contradiction on a day that was full of them — though it may have been the most portentous one.

At the level of ideas, nationalism can sound appealing. There is nothing shameful about love of one's own, the impulse that links individual self-regard and love of family to affection for one's own neighborhood, town or city, state, and political community as a whole (the nation). The social cohesion emphasized by nationalists is an important precondition of functional democratic politics as well as a necessary foundation for generous social welfare policies. Recognizing that nationalism can be taken too far doesn't make it something worthy of being erased or stamped out in the name of universal markets or humanitarianism. On the contrary, history shows that the effort to do so often generates a backlash that ends up catalyzing an even more rabid version of national attachment in response.

All of that is true, and when yesterday's speakers — including conference organizer Yoram Hazony, First Things editor Rusty Reno, and Yuval Levin of the American Enterprise Institute — hit those points, they made a lot of sense. But those are mostly points about nationalism as a background assumption for politics, not a program for how nationalism should change our politics going forward. And that is where American conservatives have a lot more thinking to do.

Are they prepared, for example, to follow the example of Fox News' Tucker Carlson — who gave a rowdy, informal rant of a talk titled "Big Business Hates Your Family"? Carlson attacked the thoughtlessness of House Republicans for abandoning American families to the rapaciousness of the market — and later (during the Q&A) endorsed Elizabeth Warren's book The Two-Income Trap, calling it "more important than everything written by social conservatives over the past 10 years." In the years leading up to Ronald Reagan's election, neoconservative icon Irving Kristol gave two cheers for capitalism. Does nationalism demand that conservatives now give it one instead? Or none? (That could complicate Republican efforts to brand Democrats as a party of socialism.)

One could ask a similar set of questions about foreign policy. Carlson, who delivered one of two keynote addresses at the conference, confessed to hating everything favored by Trump's super-hawkish national security adviser John Bolton — who is slated to deliver the conference's other keynote on Tuesday. So which is it? Should a nationalist America use its formidable military power to bully the world in pursuit of its interests, as Bolton and Trump seem to favor? Or should a nationalist America act with comparative restraint on the world stage, as Carlson believes, as many foreign policy realists advise, and as Trump (at other times) appears inclined to endorse? The names of the speakers lined up for the second day of the conference (including the Hudson Institute's Michael Doran and Clifford May of the Foundation for the Defense of Democracies) suggest that the first, hawkish group is poised to continue exercising significant influence within the conservative movement, even after a possible nationalist transformation.

But the biggest contradiction of all may follow from the character of Donald Trump's distinctive style of nationalism— and its (thus far) unhappy mixture with American politics and ideals.

In his remarks to the conference, Hazony — whose 2018 book The Virtue of Nationalism helped to inspire and galvanize it — explicitly and unambivalently denounced white nationalism. Yet he said nothing at all about the white nationalism practiced by the president of the United States. That its most recent expression took the form of a string of tweets telling his dark-skinned progressive critics (most of whom were born in this country) to "go back" to the "totally broken and crime infested places from which they came" only sharpens the issue.

In Hungary, it's possible to believe that nationalism could serve as a foundation for social solidarity — despite its own problems with xenophobia and authoritarianism — because the country's nationalist leadership (Viktor Orbán and his Fidesz Party) wins outright majorities in elections and the largest opposition party (Jobbik) is even further to the right. But that is not at all the American reality. Trump won an incredibly narrow victory in 2016, he's proven incapable of raising his approval rating above roughly 43 percent, and his every utterance sows greater division and increases polarization.

One might say that Trump's form of nationalism does the opposite of what the nationalists in attendance at the conference claim it should: It shreds social cohesion instead of shoring it up. Carlson, Reno, and others on the right can seek to blame liberal elites for this, claiming they foster hostility to the president. But that won't cut it. From the moment he launched his presidential campaign four years ago, Trump has sought to divide the nation in order to conquer it. This impulse is far more politically potent now because he actually holds power, and because his administration displays outright cruelty and incompetence on a daily basis. That he sometimes talks about unity and bringing the country together can't cover over his myriad acts of intentional divisiveness.

Social cohesion is important. Love of one's own is a necessary foundational element of democracy. But Trump's version of nationalism won't get us there. On the contrary, it's likely to leave these preconditions of decent politics much weaker than they were before he burst on the political scene — and more in need of a form of politics that can bind up the nation's wounds and help to heal it.

That is the only style of politics likely to deliver on the hopes and ambitions enunciated at the inaugural National Conservatism Conference.