Recently uncovered video reportedly featuring members and guests of the Sigma Alpha Epsilon fraternity chapter at the University of Oklahoma singing a racist song on a bus has raised the question of whether the song constitutes protected expression under the First Amendment. Unless there are more factors of which we are not yet aware, the answer is yes.
As a private organization, the SAE national fraternity is free to punish the chapter, as it has done. Other citizens and groups are free to refuse to associate with the fraternity members based on their expression, and students, faculty, and administrators may of course condemn it. If the expression itself is evidence of other unlawful activity, such activity may be investigated. But the Supreme Court of the United States has ruled time and time again that government institutions like the University of Oklahoma may not punish people for expression protected by the First Amendment.