Mark Halperin, a Top Political Journalist, Faces Multiple Claims of Harassment

Mark Halperin built an empire as journalism’s ultimate political insider, spinning the world of government into dramatic narratives of power and ambition. His best-selling books and television appearances made him one of the most prominent and highly paid reporters in the country.

That empire began to collapse on Thursday after allegations surfaced that he had sexually harassed multiple women years ago while working as the director of political coverage at ABC News.

A report published by CNN late Wednesday included interviews with five unidentified women who described Mr. Halperin making unwanted and aggressive sexual advances toward them.

It was the latest instance of harassment claims against a towering figure in American media, and the fallout was swift.

MSNBC, where Mr. Halperin was an analyst on the influential show “Morning Joe,” said he would no longer serve as a contributor. HBO dropped a planned television adaptation of Mr. Halperin’s upcoming book about the 2016 presidential election. And by Thursday evening, his publisher, Penguin Press, said in a statement that it had canceled plans for the book entirely, “in light of the recent news.”

In a statement, Mr. Halperin denied any nonconsensual contact with the women who spoke to CNN, but he apologized for his behavior with his ABC News colleagues.