Much as he has done throughout his primary campaign, Donald Trump responded with ugly, untrue comments to news of the attack at a gay night club in Orlando. PHOTOGRAPH BY KEITH SRAKOCIC / AP

In the rhetoric of Donald Trump, mendacity and cynicism compete for equal time. It is hard to say which prevailed today as the Republican Party standard-bearer, a man who pretends to the most powerful political office in the land, tweeted this at his followers: “Appreciate the congrats for being right on radical Islamic terrorism.”

This came in the wake of the most horrific mass shooting in the history of the United States—a slaughter of fifty men and women in an L.G.B.T. night club called Pulse, in Orlando, early Sunday morning. Trump allowed that he didn’t want “congrats” so much as he wanted “toughness & vigilance.” Just as profoundly, he announced, “We must be smart!”

Trump also told his followers—and hence the world—that President Obama should “immediately resign in disgrace” for failing to “mention the words radical Islam” in his remarks on the shooting. And, he suggested, Hillary Clinton might want to get out of the Presidential race for making the same sin of omission in her statement.

With every month, it has become clearer that Trump is a makeshift politician, whose rancid wit resides in his willingness to say whatever it takes to arouse the fears of a political base. He might have started his campaign with the idea of winning some votes and publicity, increasing his profile as a marketing whiz, and then dropping out. Good for business! But now that he has stunned the political world—and, likely, himself—he has shown little inclination (or, perhaps, capacity) to grow into his role, to modify his language, be it for the sake of the Republican establishment or of simple decency. He’ll have none of that. Whatever inflates his sense of self and prods the anxieties of the country—that’s what works for him.

It feels indecent on such a day to engage these comments of Trump’s at all. But their velocity, vapidity, and sheer ugliness reflect his character, his emptiness, and, most of all, the shape of the election campaign to come. Since Trump has ascended, it’s been clear that his demagogic instincts could be tested precisely by the sort of tragedy suffered in Orlando. And, when faced with the path of modesty and the path of dark opportunism, he has chosen the latter. That’s what he is about. It’s who he is.

This might have been predicted. In the wake of the attacks in Brussels, last March, Trump was asked if he would consider using nuclear weapons to fight ISIS. “Well, I’m never gonna rule anything out,” he said. “The fact is, we need unpredictability.” He said the terrorists were “winning,” and “we don’t do anything about it.” Waterboarding, he said, “would be fine.”

Now, Trump is again pounding the notion of American leadership as “weak,” as complacent.

“If we do not get tough and smart real fast, we are not going to have a country anymore,” Trump said in a statement posted on his campaign’s Web site. “Because our leaders are weak, I said this was going to happen—and it is only going to get worse. I am trying to save lives and prevent the next terrorist attack. We can’t afford to be politically correct anymore.”

Trump’s ruse is that somehow the United States is not engaged militarily in the fight against ISIS, or that “political correctness” is the chief factor undermining American security. He feeds his constituents daily with the misbegotten notion that the country is being flooded with countless unchecked “aliens” from the Middle East, South Asia, and Mexico. The mouth moves and the lies pour forth. Any contrary evidence, any complexity, is foreign. Questioned on television to prove his points, faced with contrary evidence, he talks past it. Never mind all the firepower expended against ISIS targets, the territory gained, and the difficulty of taking back cities when ordinary civilians are used, en masse, as human shields. We are weak; we are politically correct.

No one, not least the President, failed to take note that the man identified by authorities as the killer in Orlando—a twenty-nine-year-old American citizen and security guard from Fort Pierce, Florida, named Omar Mateen—had carried out a terrorist attack. Official sources also revealed that he had pledged allegiance to ISIS on a 911 call made just before the attack, and that he had legally purchased arms, including an AR-15 assault rifle, the same rapid-fire weapon used at Sandy Hook. The ISIS attitude toward homosexuals is well known: they are summarily executed, often thrown from rooftops. Trump, for his part, had nothing to say about the easy availability of weapons like the AR-15; he is deep in an embrace with the leadership of the National Rifle Association, which has endorsed him.

President Obama, in his statement, displayed a sense of calm resolution, grief, and outrage—as he has done repeatedly, after mass shootings in Binghamton, Fort Hood, Tucson, Aurora, Oak Creek, Overland Park, Newtown, Chapel Hill, Charleston, Chattanooga, San Bernardino, and elsewhere. Hillary Clinton, too, issued a statement that was rational, heartfelt, and touched on all the necessary aspects of the killings as we know them thus far—terrorism, the need to go on battling terrorism, the preposterously easy availability of guns, the victimization of the L.G.B.T. community.

The horror in Orlando was unspeakable. And we will learn much more about it in the days ahead. But today the event was made that much worse by a Presidential candidate who seeks to lead the country in complicated times and in its darker moments with self-aggrandizing tweets and hollow words.