For the complete policy please refer to: http://www.cmu.edu/policies/administrative-and-governance/separation-of-individuals-and-institutions-interests.html
The following is a summary of the policy.
The university applauds and encourages the interest of individuals and groups who wish to work as citizens through political channels for the betterment of society. However, the university is and must remain neutral on political issues. In the light of active political concerns of the members of the university community, guidelines have been developed to avoid the improper use of the institution's resources and facilities for political purposes. This is vital for two reasons: (1) to preserve the university's neutrality on political matters and its function as a center for freedom of thought, and (2) to assure that its tax-exempt status is protected.
All individuals and groups in the university community who wish to pursue political activities should follow the principles established by Organization Announcement 228-B, Separation of Individual's and Institution's Interests.