Academics largely agree. Debbie Walsh, director of the Center for American Women and Politics at Rutgers University, said that years of research have shown women running for office “have to prove their credentials more than men.”

“There is an assumption,” Ms. Walsh said, “that men are qualified.”

Ms. Nixon said that perception is internalized, too. She noted she had first been approached to run for governor back in 2010. The idea took years to sink in. “I think women ourselves feel like unless we have a Nobel Prize, written a best seller and labored in the industry for 20 years then we’re not qualified to put our hat in the ring.”

Like so many male Hollywood stars before her, Ms. Nixon is trying to turn her lack of government experience into an asset, casting herself as an outsider not “beholden to the special interests.”

“I’m not an Albany insider,” she almost reflexively declares when asked about her qualifications, in an anti-establishment strategy with echoes of Donald J. Trump in 2016. But in New York, where 75 percent of Democrats said they preferred “experience” over someone “new to politics” in a recent Quinnipiac University poll, she faces a tough audience.

If fame poses a challenge for Ms. Nixon, it has also provided much of the political oxygen fueling her insurgent candidacy.

Her launch video was seen millions of times. She recently appeared for 10 minutes on “The Daily Show,” after already chatting on Stephen Colbert’s late-night couch and Wendy Williams’s daytime program — the kind of exposure most neophyte challengers, especially ones more than 20 percentage points behind, could only dream of. And when she campaigns on crowded subway platforms, she is trailed by a crush of cameras and celebrated by commuters.