Yamiche Alcindor, the White House correspondent for “PBS NewsHour” and a former New York Times reporter, was also on the panel and responded to Mr. Brokaw’s comments.

“You’re talking about assimilation. I grew up in Miami, where people speak Spanish, but their kids speak English. And the idea that we think Americans can only speak English, as if Spanish and other languages wasn’t always part of America, is, in some ways, troubling,” Ms. Alcindor said.

Among those who criticized Mr. Brokaw was Representative Joaquin Castro, Democrat of Texas. He explained in a Twitter thread that even though there are generations of Hispanics in the United States, they are, in his opinion, never truly considered American.

“For a celebrated journalist who spent years chronicling American society you seem stunningly ignorant of the Hispanic community in this country,” Mr. Castro tweeted. “Unfortunate to see xenophobia pass for elevated political commentary.”