So if Duke wanted to make a rule excluding all African Americans or make a rule that required homosexuals be immediately expelled or that did not allow any leftists to attend that would be ok? This “make its own rules” nonsense only applies if it fits the leftist agenda. Universities must comply with all kinds of government laws and regulations.
That is why Hillsdale College refuses to accept Federal Funding.
Of course Duke must comply with many rules and regulations, but there is nothing in that policy that would seem to violate any such regulations. As I said, Duke could go much farther with its policy. Some religious schools forbid any sex outside of marriage on their campuses and it is perfectly legal for them to do so. I remember, maybe 10 years ago, a (non-Mormon) BYU football player was expelled for having consensual sex on campus.
At Manhttan College, maybe 10 years ago, 2 star basketball players were expelled for having consensual group sex with one or more female players in the dorm.