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

The stated theme of President Trump’s State of the Union was compromise. Was his speech convincing? The philosopher Aristotle taught that the persuasive qualities of oratory flow from a combination of the line of argument, the character of the speaker and the emotional orientation the speaker conveys to the audience. For instance, to believe a speaker, you have to think that person directs goodwill toward you. The president said “compromise,” but does his character and did the emotional tenor of the speech back up that stated claim?

They did not.

With lighthearted banter, the president first beamed goodwill at his Democratic colleagues, particularly when celebrating the historic number of women elected to the House in 2018. But then he delivered an uncompromising line on abortion and hot words about socialism. He assumed the stance of an adversary, announcing the grounds on which he intends to defeat Democrats in 2020. In shifting so quickly from friend to foe, he undermined whatever intention he may have had to convey a durable commitment to compromise.

But the single greatest liability in the president’s speech was, as always, his character. His words are changeable. Only a very few (“build the wall”) persist from one week to the next. His basic mode is hyperbole. At this point, none of us has much reason to take more than a few of his words seriously.

So that leaves us without a president who can be the leader of compromise.

Nevertheless, in various ways the speech did dance across territory in which we the American people can make compromises among ourselves, if we take that work on.

From that perspective, the most important portion of the speech was its pivot from the stirring account of the First Step Act and bipartisan achievement on criminal-justice reform to the president’s case for securing our borders.

The speech deftly conveyed the moral issues in criminal-justice reform. The war on drugs led to excessive sentences that have ruined communities and lives; our country is a redemption country. The First Step Act helps us recover that moral purpose and see the humanity in those who have been incarcerated for too long. We the people have been feeling our way toward compromise in this space for some time. The speech’s pivot to immigration was meant to cast immigration in the same light as criminal-justice reform — as a moral issue through which we can deliver fundamental human goods and heal ourselves as a society. The idea seemed to be that if we can see it that way, we ought to be able to find a compromise and, as with the First Step Act, achieve bipartisan legislation.

The problem is that the president and his team have misdiagnosed the moral issue concerning immigration. The moral problem is not that people cross the border illegally, demonstrating their commitment to lawlessness and then extending it to criminal acts in the country. Fact-checkers galore have pointed out that undocumented immigrants are less likely to commit crimes than native-born Americans; that flows of migrants into the country have been decreasing; and that at the moment, the families we see arriving are trying to come legally by means of asylum claims. The facts don’t support Trump’s narrative.

The true moral issue at stake in illegal immigration is that our domestic appetite for drugs, coupled with our strategies in the war on drugs, have destabilized already fragile governments throughout Central and South America. An important new book, “Shadows of Doubt,” by two economists, Brendan O’Flaherty and Rajiv Sethi, reviews the evidence for the effect of prohibition on violence, and finds that prohibition — whether of alcohol in the late 19th and early 20th centuries or of drugs in the 20th and 21st centuries — leads to an increase in homicides, and therefore to violence more generally. We ourselves are the causes of the flows of migrants to our borders. The moral issue at stake in immigration is our hypocrisy about how our own actions fuel the humanitarian crisis at our border.

If we the people can face what is actually at stake in immigration, we might be able to work our own way to a compromise on this issue.

This is especially the case since the solution to our immigration problem is actually, to a meaningful degree, the same as the solution to our criminal-justice issues. We need a full transition of our approach to illegal narcotics from a criminal-justice paradigm to a harm-reduction paradigm. The kinds of compromise that made the First Step Act possible are the same kinds that we need to address the humanitarian crisis on our border.

We can change the dynamics of the flows of migrants with changes to our policies on illegal narcotics and with a redoubled effort to help rebuild stable governments in Central and South America.

Because our problem lies within, a wall cannot fix it. Only a clearer moral purpose can.

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