I'm not sure what the policy is at my school (I'll check unless anyone beats me to it), but I think every club has to be in principle open to everybody. So for instance, Amish people are free to join the electronics club (they're not going to, but anyway).
For some people in other, far-off places, such openness is not enough freedom. They want to be free to have a club free of people who don't take their pledge. Luckily, patriots such as these have Big Idea Man and Disgraced Former Speaker of the House Newt Gingrich to watch out for them:
At the outset of the dispute and well into the initial stages of litigation, Hastings said that CLS had violated the university's bans on religious and "sexual orientation" discrimination. After CLS noted that the law school allowed other groups to organize around nonreligious ideas, Hastings suddenly asserted that no group could exclude anybody for any reason. So the Young Democrats, for example, are apparently required to accept Republicans as members and allow them to be elected to leadership positions in their club. That's simply absurd.
Moreover, it's a ploy contorted to camouflage the double standard being applied to CLS simply because it is a Christian organization. Hastings officials hope to hide the fact that on their campus, as at countless other colleges and universities nationwide, people of faith are being deliberately marginalized and excluded not for any real misdemeanors but for having the temerity to suggest that there's an authority higher than school administrators, a truth more compelling than the latest government-dictated cultural doctrine, and a God more worthy of worship than the idols of the left.
A lot of leftists — in the offices of government and in the halls of academia — seem to find those ideas laughable. And yet, watch their faces in the courtrooms and classrooms. They're not laughing. When it comes to eroding freedom to shore up their own politically correct agenda, they are deadly serious.
Being subject to the same rules as everyone else is not usually grounds for marginalization–but what do I know? My "equal protection" intuition is likely just the "latest government-dictated cultural doctrine."