The American president serves two functions in our civic life: head of government and head of state. The head of government is the country’s chief executive, making and implementing policy. This is a political job, and usually half the country disagrees with how the president is doing it.


The head-of-state role is simultaneously less and more vital than the head-of-government task. The head of state’s job is often ceremonial, greeting fellow heads of state, attending ceremonial functions like the D-Day anniversary, and the like. This function is not terribly important (though this function also produced the single-greatest piece of presidential rhetoric in American history). Then there are national traumas, disasters that seem senseless, in which ordinary citizens look to leaders to help make sense of the world. For my generation, the first prominent example of this was Ronald Reagan’s televised address to the nation following the explosion of the Challenger space shuttle.


This function is now an expected feature of the modern presidency, as political scientists Julia Azari and Jennifer Smith noted a few years ago:


“The expectation that the president will “do something” about an issue is now often fulfilled precisely by speaking about it, and media actors are prominent enforcers of this expectation. As a result, contemporary presidents go public even when their political capital is depleted (George W. Bush on the 2008 Emergency Economic Stabilization Act), when issues exceed their constitutional authority (Barack Obama on Wisconsin budget repair), and when events are beyond executive authority of any kind (Obama on the Tohoku earthquake). In so doing, they conform to an unwritten rule about the responsibilities of the office they hold.”


And this brings us to the tragic events of this past weekend: the deadly shootings in El Paso, Texas, and Dayton, Ohio. In the case of the alleged El Paso shooter, it would seem that he was inspired by white nationalist rhetoric that stresses a Hispanic “invasion” of the United States. These shootings captured enough attention that even my 14-year-old daughter, someone not prone to paying much attention to the national news, asked me about it.


These are moments when a president can and should attempt to use their bully pulpit to reassure the nation that as the country mourns, action will be taken. As president, Barack Obama was asked to do this all too often. Most of the time he was brilliant at it; sometimes he faltered. The important thing is that the man tried every time. Obama understood his function during these moments of trauma, and endeavored to speak for all Americans at such times. Obama was hardly unique; with the occasional exception, the 42 men who preceded him performed the same function.


Commentators can debate all day about Donald Trump’s performance as the head of government. But there is a rare degree of unanimity that the 45th president is not just a bad head of state; he is essentially incapable of performing that function. This had been clear long before this weekend. Indeed, a few months ago, The New York Times’s Peter Baker suggested that Trump had destroyed this element of the U.S. presidency: “The old-fashioned idea that a president, once reaching office, should at least pretend to be the leader of all the people these days seems so, well, old-fashioned. Mr. Trump does not bother with the pretense. He is speaking to his people, not the people.”


All this was before Trump had launched his persistent, racist tirades against minority members of Congress. Trump’s bigoted rhetoric is about as far from unifying as politically possible. He doesn’t bring the country together - he lacks the ability to do that. The only thing Trump does with his words is inspire domestic extremists and stress the rest of America out. This holds with particular force for the El Paso shooting. As former Department of Homeland Security official Juliette Kayyem tweeted out, “[Trump] doesn’t shame white supremacists. He both-sides them, winks and nods them, tolerates, embraces, goads, lures, flirts … call it what you will. But he does not shame it.”


As further proof of his inability to do this part of the job, Trump was completely missing in action this weekend - except for Twitter. On that platform, he tried to mimic what a head of state would say, but it came across as tone-deaf; the exclamation points never help in these situations.


In that tweet, Trump does not sound like the president. He sounds like a man parroting the cable news he is watching. Despite the carnage wreaked in Dayton and El Paso, the president stayed at his golf club and made no public appearance. I am sure that in the next few days he will have no choice but to say something appropriate for the occasion. Let’s be honest, however: Trump cannot deliver a speech on this topic with any kind of feeling. He lacks the sentiment, and he lacks the ability to fake it. When it happens, it will be a pathetic display.


The growth of homegrown white nationalism preceded Trump, but his administration has made the problem worse with its rhetoric and staffing decisions. There will and should be debates about the best set of policies to cope with this burgeoning problem. Maybe something will get done; maybe the people acting as impediments to doing something will be voted out.


For now, however, what matters is that America is hurting. Unfortunately, we lack a leader with the ability to serve as a head of state. We have a man who cannot comprehend grieving. All he understands is grievance.


Daniel W. Drezner is a columnist with The Washington Post.