That became painfully clear last Wednesday when, after his stunning setback on Super Tuesday, Mr. Sanders bent the knee and submitted to a barrage of not particularly friendly questions from the most powerful progressive on TV, the MSNBC host Rachel Maddow.

He had been avoiding the network, suspicious of its wealthy hosts and corporate owners. He told Ms. Maddow in mild exasperation that one of his challenges was “taking on the corporate media, if I might say so.”

It was clear the primary voting had shaken the Vermont senator’s whole theory of the election — that he could mobilize a huge new cohort of young people.

At the same time, the events of the past week have validated much of his criticism of the media, the subject of a 1988 town hall with Mr. Sanders and the radical provocateur Abbie Hoffman. Mr. Sanders complained that Vermont’s television stations had been “prostituted by commercials.” (The video is a trip, and worth the click.)

His main point: “The media itself is as important a political issue as exists.”

Mr. Sanders is right about that, and about two other big things: that much of the U.S. media still covers elections as if they’re sporting events and that the affluent New Yorkers who run and appear on television networks are not inclined to like him. The narrative of Joe Biden’s comeback was an irresistible story to the media — one that often eclipsed the coronavirus, never mind discussion of health care or poverty — on cable news in recent days.