Anderson Cooper was reading the names of victims of the Orlando massacre on CNN this week when, uncharacteristically, his voice wavered and he drew up short. For moments, viewers around the country heard only silence, and then the sounds of the anchor struggling to compose himself.

“That was horrible,” Mr. Cooper recalled, a bit sheepishly, in an interview on Wednesday. Accustomed to covering foreign wars and lethal hurricanes, Mr. Cooper said he did not like to show his feelings on camera.

But this time, he added, felt different: “I’ve been surprised at how emotional this has been.”

As the news industry descended on Florida this week in the aftermath of a mass shooting in a gay nightclub, Mr. Cooper’s raw, activist-style coverage has stood out. He has held a prime-time vigil of sorts, reciting a list of the dead; refused to name the gunman, saying he wanted to focus on victims; and, in a widely viewed exchange, grilled Florida’s attorney general for defending a state ban on same-sex marriage.

Mr. Cooper, who is gay, has seemed to embrace an advocacy role rarely seen among top network anchors, blending on-the-ground reporting with a distinctly personal and empathetic touch.