He said every day she was in the race was a good day for Mr. Trump. “She embodies the wackiness of all of the Democrat policy proposals,” he said in an interview. “Love is great, but it doesn’t put food on the table. The more she is involved, the further it cements in the minds of Americans that these ideas that Democrats are proposing are literally out of left field.”

After the first Democratic debate in June, Jeff Roe, the Republican strategist who served as Senator Ted Cruz’s campaign manager in the 2016 presidential race, urged Republicans to donate $1 to Ms. Williamson’s campaign to “keep this vibrant Democrat on the debate stage.’’

“One debate performance is not enough,” he added.

Mr. Roe, who described himself in an interview as “the self-appointed president of the Republicans for Williamson fan club,” said the author was “fairly loony, but represents the heart of what the Democratic Party is talking about when the moderates on the stage are talking about taxing the rich and doing universal health care.” Ms. Williamson’s ideology, he said, “is in the middle of the mainstream.”

In such an oversaturated, fast-paced news cycle, this burst of attention may prove ephemeral for Ms. Williamson. And the limelight has not always been kind to her; she has drawn scrutiny, and criticism from the medical community, for her controversial positions on mental health, vaccines and antidepressants.

But Tuesday’s performance was no doubt a moment for her. She was the No. 3 most-searched topic over all on Google on Tuesday. None of her rivals cracked the top 10. Data provided by Twitter showed that she spurred the fourth-most posts of all the candidates onstage, a significant burst of recognition for someone who has struggled to hit 1 percent in the polls.

Her impassioned critique of the Democratic Party as tone deaf to the everyday concerns of struggling minority communities was the third-most commented-on moment of the debate, according to Twitter. Turning to everyone on the stage, Ms. Williamson dismissed “this wonkiness” in the policy solutions put forward by her rivals, and said that if marginalized people did not believe Democrats were standing up for them, “they won’t vote for us and Donald Trump will win.”

Some warned that the pundits and politicians may not have it right with their appraisals of Ms. Williamson’s appeal — a not-so-subtle reminder that groupthink derision has led to serious mistakes in the past.