The Fix's Chris Cillizza explains the two presidential nominees' responses to the June 12 mass shooting in Orlando, Fla. (Peter Stevenson/The Washington Post)

A man who reportedly pledged his loyalty to the Islamic State murdered 50 people at a gay nightclub in Orlando early Sunday morning, making it the single most deadly mass shooting incident in American history.

Donald Trump, the presumptive Republican presidential nominee, tweeted his reaction on Sunday afternoon:

Earlier, he tweeted:

But he also used the opportunity to take a shot at President Obama:

Just by way of comparison, here’s what Hillary Clinton, the presumptive Democratic nominee, tweeted in reaction to the shootings:

The difference in tone is striking. Clinton was empathetic and sorrowful. Trump was triumphant and aggressive.

Trump’s tweet speaks to the single largest problem facing his presidential campaign: While he’s mastered the role of tough and unapologetic leader, he simply cannot seem to understand that at times a president needs to be an empathetic consoler in chief, too.

The job of president is a deeply complex one. You must be able to play both roles. Increasingly, given the number of mass shootings happening in the United States, President Obama has found himself in the consoler in chief role — the person who acknowledges the fear, anxiety and hurt but also insists that this is not who we are.

President Obama made a statement on the shooting in Orlando from the White House briefing room. (AP)

Some of Obama’s most powerful moments as president have come amid tragedy. His eulogy following the shooting deaths of nine churchgoers in Charleston, S.C., was one of the best speeches of his presidency. His address in the wake of the 2011 shooting of then-Arizona Rep. Gabrielle Giffords (D), in which 13 people were injured and six killed, ranks as one of his most poignant.

Trump’s tweet feels decidedly off in the context of the tragedy playing out in Orlando. That people are congratulating him about being right about the threat posed by the Islamic States feels like the sort of thing that could have certainly waited a few days — or forever — to publicize. Making a moment like this one about yourself — “I was right!” is the essence of Trump’s tweet — is a giant swing and miss when it comes to understanding what the broader nation requires of its leaders.

For those hard-core Trump supporters, this tweet will change nothing about how they view the real estate mogul. Nothing could — or will. The problem for Trump is that there are not enough hard-core Trump supporters for him to win a general election. Not even close.

Trump needs to grow his coalition to convince people that he can not only rile up his supporters with big pledges (build a wall and make Mexico pay for it and temporarily ban Muslims from entering the United States) but that he can also do all of the other important tasks required of a president including comforting them in their sorrows.

A gunman opened fire on a crowded nightclub in Orlando early Sunday, June 12. He killed at least 49 people. The final death toll is not known, but this shooting is already the deadliest mass shooting in the history of the United States. (Monica Akhtar/The Washington Post)

There’s ample evidence — long before today’s tragedy — that Trump struggles mightily on questions of empathy. Asked which candidate “better understands the problems of people like you,” 47 percent of registered voters in a late May Washington Post-ABC News poll chose Clinton, while 36 percent named Trump. On the question of who better represents “your personal values,” 48 percent chose Clinton, and 37 percent went with Trump.

His tweet — and the mind-set that led to it — won’t reassure anyone on that front.