Bed Bath & Beyond and Kohl’s cited the brand’s poor performance for their exits, while Today’s Shopping Choice did not comment beyond confirming the removal. Wayfair declined to comment, and H-E-B did not respond to requests for comment. Zulily said it stopped carrying MyPillow in July. Affirm, the financing start-up, separately confirmed that it severed ties with MyPillow last week.

Matt Rivitz, a co-founder of Sleeping Giants, said the claim about bots was “ridiculous.” Throughout the Trump presidency, he said, consumers grew more aware of their collective power, beginning with ads on Breitbart and boycotts of Ivanka Trump products at Nordstrom. This has been the culmination of those efforts.

“There were a number of videos that came out with Lindell doing these rants about how the election was stolen and clearly that led to violence,” Mr. Rivitz said. “It was just a natural inclination to ask companies if they supported that because ultimately these companies have greatly benefited from democracy and they likely don’t want to see the country fall into chaos because of these lies.”