FRANKLIN D. ROOSEVELT won four presidential elections, but there was one vote that eluded him. As a Harvard undergraduate, he “punched”—sought to join—the Porcellian, the oldest of Harvard’s eight private, historically all-male “final clubs”. Even though it had previously admitted his father and his cousin Theodore, he was rejected. Now Drew Faust, Harvard’s president, is attempting to tame the secretive organisation as even the Roosevelt clan could not. On May 6th Ms Faust announced that the college would punish students who join single-sex social clubs.

America’s oldest university was historically an exclusively male domain. It did not educate women until the founding of Radcliffe in 1879, which did not merge with Harvard itself until 1977. As expectations of sexual equality evolved, Harvard followed suit, and demanded that its social clubs go co-ed. They refused, and in 1984 the college cut ties with them.

Once Harvard’s relationship with the clubs was severed, however, its administrators lost all power to influence them. As a result, the final clubs have continued to play a dominant role in the college’s social life without any external oversight. By the late 1990s female students began setting up their own single-sex organisations. Today, a quarter of undergraduates belong to a social club. Since 2014, two male clubs opened their doors to female members.

But in recent years activists and the press have devoted increasing scrutiny to the spectre of rape on campus. In March Harvard published an official inquiry into sexual assault, and found that 47% of women in their last year of study who had attended final club events (including female-hosted ones) said they had experienced non-consensual sexual contact in college, compared with 31% for senior women overall. Defenders of the clubs said the study conflated correlation with causation—it did not determine whether these unwanted encounters occurred in the clubs or elsewhere, or whether the perpetrators were club members. The report’s authors accused the clubs of “deeply misogynistic attitudes” and a “strong sense of sexual entitlement”.

Even the clubs’ critics, however, had reason to be surprised by Ms Faust’s response. Although Harvard cannot control unaffiliated private organisations, it still wields power over other aspects of student life. So rather than targeting the clubs, Ms Faust went after their members. She announced that from 2017, members of single-sex clubs, fraternities and sororities will not be allowed to lead official campus groups or captain sports teams. Nor will they be eligible for some scholarships. Harvard, she said, could not “endorse selection criteria that reject much of the student body merely because of gender”.

The final clubs protest that the university is violating their First Amendment right to freedom of association. One may challenge the policy in court—though such a claim is unlikely to get far, since Harvard is itself a private institution, with the same freedom to establish rules for its students that final clubs do for their members. In the case of the all-male Porcellian, which does not allow guests of any gender past its reception hall, its former graduate board president Charles Storey has noted that forcing it to admit women “could potentially increase, not decrease, the potential for sexual misconduct.” Sororities are not happy with the decision either. They marched through Harvard Yard on May 9th, declaring that all-female clubs provide a much-needed “safe space” for women.

Even if the statistical evidence tying the clubs to sexual assault is contested, Ms Faust has good reasons to pressure them to go co-ed. Despite the proliferation of sororities and female final clubs, only the male clubs boast luxurious mansions scattered around Harvard’s campus, out of the reach of police enforcing under-age drinking laws. This disparity entrenches Harvard’s retrograde tradition of privileges for men.

But the main reason Ms Faust’s predecessors left the clubs in peace is that the new edict may be unenforceable. Final clubs do not publish membership lists. Will the college plant spies at their events? Or reward students who rat out their roommates with extra helpings in the dining hall? Harvard may end up proving the law of unintended consequences taught in its economics courses: as Peter Ayala, a student, notes, the rule could cause the clubs to become more secretive than ever.