In a YouTube video that was uploaded about a month before the election, a young, blond man in baggy jeans and a graphic T-shirt sits alone at the center of a circle of folding chairs.

One by one, people approach him to debate issues like abortion, inflation and whether former President Donald J. Trump’s policies would benefit the middle class. The video, titled “Can 1 Woke Teen Survive 20 Trump Supporters?,” has been viewed more than 14 million times since it was posted by the debate-centric media company Jubilee.

The “woke teen” in question is Dean Withers, a now-20-year-old liberal content creator who lives in Colorado. Mr. Withers has been debating politics online since 2022 but rapidly gained traction in the final stretch of an election in which Republicans improved their performance with young men.

Gen Z men have reported feeling economically dissatisfied and socially left behind, frustrations that President-elect Trump sought to channel with the help of an online “manosphere” of podcasters and influencers. In the aftermath of an election in which many Democrats believe they were outflanked online, some are scrambling to find bro whisperers of their own.

They are eyeing people like Mr. Withers, who attended a holiday reception at the White House on Tuesday. (“Off to meet mr joe,” he wrote on his Instagram story beforehand.)

He is part of an ecosystem of left-leaning influencers including Hasan Piker, the 33-year-old progressive commentator who streams for hours a day on Twitch. An even younger group of men including Harry Sisson, Mr. Withers and a friend known online simply as Parker each have more than a million followers on TikTok, where they brawl with supporters of Mr. Trump during combative, unpredictable livestreams that Mr. Withers compared to U.F.C. matches.