Mr. Teixeira calls the Democrats’ problem with critical race theory and other galvanizing issues the “Fox News Fallacy.”

These issues are ripe for distortions and exaggeration by Republican politicians and their allies in the news media. But Mr. Teixeira says Democrats should not dismiss voters’ concerns as simply right-wing misinformation.

“An issue is not necessarily completely invalid just because Fox News mentions it,” he said.

In an interview, Mr. Teixeira said his logic applied to questions far beyond critical race theory. “I can’t tell you how many times I analyze a particular issue, saying this is a real concern,” he said. “And the first thing I hear is, ‘Hey, this is a right-wing talking point. You’re playing into the hands of the enemy.’”