When the awful news broke about the terrorist attacks in Belgium, the “Today” show asked Donald Trump to call in, which he promptly did.

Matt Lauer said the NBC show also asked for a phoner with Hillary Clinton, and she declined. Later, though, she apparently had a change of heart and phoned in as well.

A small thing, to be sure, and I hesitate to inject presidential politics into a tragic event that left more than 30 people dead at the Brussels airport and a subway station. 

But terrorism is a central issue in this campaign, and the news came on a day when Utah, Arizona and Idaho were voting in primaries and caucuses.

The fact that “Today” and “Fox & Friends” had Trump call in underscores how he’s now thought of as a potential commander-in-chief. When he told Lauer that “I would be very, very tough on the borders,” it was a reminder that Trump’s terror talk—bomb the S out of ISIS, temporarily ban Muslims from entering the U.S.—has boosted his popularity among Republican voters.

Trump’s aggressive stance—he called Brussels “a total mess” and also talked about the need to waterboard terror suspects—set up a stark contrast with the former secretary of State. She said that torture is not effective and would put our own citizens and soldiers at risk. And, Clinton said, “It's unrealistic to say we're going to completely shut down our borders to everyone. That would stop commerce, for example, and that's not in anybody's interest.” She also phoned in to “Good Morning America.”

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The death toll in Belgium is going to change the tenor of the campaign for some time to come, even though it is difficult to hold the Obama administration accountable for every attack around the world. The president was out of position, going through the planned activities on his historic visit to Cuba. He asked his Cuban hosts to “please indulge me” as he devoted a total of six sentences to condemning “these outrageous attacks against innocent people.”

That is reminiscent of Obama’s tepid reaction to the Paris attacks, which caused him to try several more times to appear more empathetic. The Paris massacre, followed by the mass killing in San Bernardino, also transformed the campaign and, in my view, helped Trump. But given the media’s notoriously short attention span, coverage of those two calamities eventually faded as the campaign turned into a festival of insults.

Ted Cruz and John Kasich also responded aggressively to the Belgian bloodbath yesterday, but the twin “Today” invitations to the front-runners tells you something about how the media view the race.

While Clinton can draw on her diplomatic experience in talking about terror, she is to some degree hamstrung by the need not to break openly with the president she served.

The violence in Brussels took place hours after Trump, Clinton, Cruz and Kasich—but not Bernie Sanders—addressed AIPAC and spoke of the U.S. role in protecting Israel. The attack on a NATO ally also happened the day after Trump told the Washington Post that the U.S. should diminish its role in NATO and is bearing too much of the financial burden—something we’re likely to hear more about in the coming days.

Indeed, Clinton later told MSNBC that some candidates don't understand the importance of NATO.

The media have been obsessed lately with delegate math and the skirmishes that have broken out at Trump rallies. Unfortunately, it took far more damaging violence to remind everyone of the stakes in this campaign.

Howard Kurtz is a Fox News analyst and the host of "MediaBuzz" (Sundays 11 a.m. and 5 p.m. ET). He is the author of five books and is based in Washington. Follow him at @HowardKurtz. Click here for more information on Howard Kurtz.