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“Bye-bye Tucker Carlson!” T-Mobile CEO Mike Sievert tweeted earlier this week in response to consumers who criticized the advertisers on Carlson’s show.

Sievert said on Twitter that T-Mobile hasn’t bought any air time on “Tucker Carlson Tonight” for “about a month, and we won’t be in the future, either.”

Carlson’s Fox News show has once again become a target of critics and a no-go zone for some advertisers. Liberal groups have called out Carlson’s advertisers and encouraged customers to take action.

The proximate cause: Carlson’s comments about the Black Lives Matter movement. “This may be a lot of things, this moment we’re living through, but it is definitely not about black lives,” Carlson said Monday night. “Remember that when they come for you, and at this rate, they will.”

What many people heard Carlson telling his nearly 100% white audience was black-people-are-coming-for-you. The next day, Fox came out with a statement attempting to clarify: “Tucker’s warning about ‘when they come for you’ was clearly referring to Democratic leaders and inner city politicians.”

Media Matters, an advocacy group that opposes Fox, re-shared a list it keeps of Carlson’s sponsors. Sievert from T-Mobile spoke out on Tuesday. Papa John’s Pizza said on Wednesday it would halt future advertising.

The latest ad boycott effort has caused new headaches inside Fox, according to sources at the network. It is unclear if the impact is more or less significant than past campaigns against Carlson.

At this point, many large national brands avoid Carlson’s 8 p.m. talk show, even though it is among the highest-rated shows on cable television, which would normally make it an attractive place to run ads.

Carlson’s right-wing commentaries about immigration caused a pressure campaign by liberal activists and led many advertisers to retreat in late 2018.

At this point, the show has relatively few big-name advertisers, according to data from iSpot, an ad measurement firm.

Between June 1 and 10, Carlson’s biggest sponsor by far was MyPillow, a brand closely aligned with Fox News as a whole. MyPillow ran 120 spots on Carlson’s show, while the next biggest advertiser, Relaxium, ran 28 spots. The third most frequent advertiser was Fox News itself, with promos for other shows, followed by Fox Nation, with promos for the company’s streaming service.

Other sponsors on Thursday’s edition of the show included Leaf Filter, Sandals, Tommie Copper, and Fisher Investments.

A Fox spokesperson reiterated what the network has said on past occasions when Carlson’s show has been scrutinized: That the pressure campaigns do not hurt the bottom line.

Any advertiser who wanted to shift out from the 8 p.m. time slot has “moved to other programs and Fox News hasn’t lost any revenue overall,” the spokesperson said.

Fox’s statement, however, doesn’t account for missed opportunities. If there was robust demand to run ads during Carlson’s high-profile time slot, Fox would be able to charge more and pack more ads into the show, thus boosting revenue.

Carlson, who is close to Fox Corp CEO Lachlan Murdoch, continues to have the support of management.

The company’s position, as expressed in late 2018 and again in 2019, is that “we cannot and will not allow voices like Tucker Carlson to be censored by agenda-driven intimidation efforts.”