SAN DIEGO — Rich Allison is a former Marine Corps captain who was never in combat. Now he is on the front lines of the culture wars.

Mr. Allison, 47, is a key player in a movement of men’s rights activists challenging female-focused businesses, marketing strategies, educational programs and civic projects that have surged since the election of President Trump in November 2016 and the #MeToo movement.

He has been a plaintiff in 13 lawsuits, most of which cite discrimination against men in violation of California’s Unruh Civil Rights Act, named for the politician Jesse Unruh, known as “Big Daddy.” It outlaws discrimination against all people by any type of business establishment in the state, regardless of a person’s sex, race and other characteristics. Mr. Allison and his cohort would like to remind everyone that Unruh’s broad promise of “full and equal accommodations, advantages, facilities, privileges or services” extends to men.

“I believe in social justice and fairness,” Mr. Allison said.

Since September 2017, he has filed three suits, including one last month against Financial Services Information Sharing and Analysis Center, a nonprofit that helps the financial services industry with physical security and cybersecurity. In 2016, the organization started a “Diversity Scholarship” that awards female recipients $5,000 apiece, along with covering the costs of attending an industry conference.