Homeland Security Secretary Kirstjen Nielsen told reporters Monday that she had not seen images of migrant children being held without parents at a converted Walmart in Brownsville, Tex. — a dubious claim, given that “they've been aired all over national television” for days, as NBC's Kristen Welker pointed out.

Nielsen also said she had not heard an audio recording of children crying after being separated from their parents — a more plausible claim, given that ProPublica published the tape only 80 minutes before the secretary addressed the media at the White House.

Despite her professed unfamiliarity with the materials, Nielsen knew enough to suggest that their circulation reveals media bias.

“I think that they reflect the focus of those who post such pictures and narratives,” she said. “The narratives we don't see are the narratives of the crime, of the opioids, of the smugglers, of people who are killed by gang members, of American children who are recruited and then, when they lose the drugs, they're Tased and beaten. So we don't have a balanced view of what's happening.”

Nielsen's argument is flawed in two significant ways.

One: The photographs and videos from the Brownsville facility were distributed by President Trump's own administration, whose “focus” is, presumably, not on casting itself in a bad light. Journalists toured the holding center last week but were not permitted to take photos or videos.

ProPublica obtained the recording of distraught children through a civil rights lawyer, who said she got it from a client.

Two: The media have, in reality, reported at length on opioids, smugglers and gangs crossing U.S. borders — often correcting the president's exaggerations. Whether the coverage has been sufficient is a matter of opinion, but it is untrue that those are “narratives we don't see.”

Nevertheless, it is worth evaluating Nielsen's apparent contention that by showing images of detained children (whatever the source) and by publishing a tape such as the one obtained by ProPublica, the media are trying to trigger emotional responses that will swing public opinion away from the Trump administration's “zero-tolerance policy.”

ProPublica President Richard Tofel pushed back on Twitter, saying, “Our agenda is to bring the American people facts for their consideration.”

The sound of wailing children is not a conventional fact, but ProPublica's Ginger Thompson made the case, in her report on the tape, that it qualifies as important information:

An audio recording obtained by ProPublica adds real-life sounds of suffering to a contentious policy debate that has so far been short on input from those with the most at stake: immigrant children. . . .

In recent days, authorities on the border have begun allowing tightly controlled tours of the facilities that are meant to put a humane face on the policy. But cameras are heavily restricted. And the children being held are not allowed to speak to journalists.

The audio obtained by ProPublica breaks that silence.

The counter to Nielsen, in other words, is that the media's job is to help voters develop informed opinions. The purpose of human-interest reporting that pulls heartstrings is not to tell voters to reject the Trump administration's policy but rather to ensure that even those who support it do so fully aware of its effects.

NBC aired part of the ProPublica tape on its nightly newscast Monday, and anchor Lester Holt closed the show with a message in which he said, “There's nothing political about wincing or shedding a tear at the sight of a child left alone, one caught up in dizzying circumstances not of their own making, and crying for their families.”

Still, the line between reporting and advocacy is thin. CNN also aired part of the ProPublica tape Monday evening, right before Wolf Blitzer interviewed White House legislative affairs director Marc Short. After about eight minutes of tough questioning, Blitzer appeared to slip in his own opinion.

Blitzer asked Short why, considering the opposition of some prominent Republicans to family separations, the Trump administration won't end the practice. But Blitzer phrased the question like this: “Why not simply do the right thing?”

“I appreciate your editorializing about what is the right thing to do or not,” Short replied.

“I'm not editorializing,” Blitzer insisted. “I'm reflecting the views of an overwhelming majority of the American public.”

Two-thirds of Americans do oppose family separations, but Blitzer signaled that he is among them when he described reversing the Trump administration's policy as the “right thing” to do. It was the sort of moment that bolsters Nielsen's implication that the news media are not merely trying to “bring the American people facts for their consideration,” as Tofel put it, but also telling people what to do with those facts.