The right to free association is dead.
I think the key is, that it’s on Uncle Sam’s dime. Pay the piper, call the tune. Yeah, they could get slapped by the USSC as many a time before. But conservative students can stop this at a local level PDQ by punking liberal groups that now have to be open to them.
While it sucks that Satan is having his way, the Lord said it would be so and we waste time and energy fighting this system - Christians can do more good by finding a way to unfetter themselves and not paying so much attention to worldly roadblocks. Satan will rule the worldly until Jesus returns to straighten him out - the Lord has said as much, yet we continually beat our heads against the wall trying to resist the evil that Jesus told us not to resist.
As citizens, we can campaign/lobby/vote - as Christians, we need to find the separation of worldly things and the Good News we are supposed to be spreading.