Gov. Gavin Newsom of California, embarking on a personal post-mortem of the failures of his Democratic Party, suggested this week that the participation of transgender athletes in women’s sports was “deeply unfair.”

The comments by Mr. Newsom, who has backed L.G.B.T.Q. causes for decades and was one of the first American elected officials to officiate same-sex weddings, represented a remarkable break from other top Democrats on the issue, and signaled a newly defensive position on transgender rights among many in his party.

Just as surprising as Mr. Newsom’s remarks was the person to whom he made them: Charlie Kirk, a 31-year-old right-wing influencer best known for starting Turning Point USA, the pro-Trump organization that is active on college campuses.

Mr. Newsom invited Mr. Kirk, who has a history of inflammatory and conspiratorial remarks, onto the debut episode of his new podcast, “This Is Gavin Newsom,” for an 81-minute discussion. The governor, who has long been fascinated with the conservative media ecosystem and tried to inject himself into it, explained his unlikely guest by saying, “People need to understand your success, your influence, what you’ve been up to.”

Mr. Newsom is widely seen as having presidential ambitions in 2028 — something he joked about on the podcast. For years, he was one of the fiercest Democratic antagonists toward President Trump, casting himself as a next-generation liberal warrior fluent in conservative orthodoxy who could lead his party into the post-Biden era.