Olivia Nuzzi, a well-known writer for New York Magazine, has accused her ex-fiancé, Ryan Lizza, a prominent political journalist with Politico, of harassing and blackmailing her after their relationship ended. According to Nuzzi, this harassment began while she was secretly involved with Robert F. Kennedy Jr. (RFK Jr.), a former presidential candidate.

In a court filing made in Washington, D.C., Nuzzi claims that Lizza threatened to expose personal details about her to damage her reputat...