Why sue?
The frat boys will sit out a year, spend their days at the country club playing golf and go to Texas Tech next year.
However, they will not get on the stand to defend their right to say:
“There will never be a nigger SAE/There will never be a nigger SAE/You can hang him from a tree/But hell never sign with me/There will never be a nigger SAE.
But they have that right. It's political speech with a small "P," however uncharitable. And note that it's being punished for political, rather charitable reasons.
Ask not for which unprotected class, such as "frat boys," the right to free speech is withdrawn. It is withdrawn for thee.