The Commission on Presidential Debates (http://www.debates.org) is a Private organization that is Co-Chaired by one Republican and one Democrat. The CPD maintains control over the rules for debates between candidates, and sets the rules to effectively block all other legitimate candidates from participating.
As a result, only candidates from the Republican and Democrat parties are ever included in the debates. The purposeful exclusion of other candidates is unfair, and is a great disservice to all of the citizens of the United States.
The CPD should be replaced with a system that allows for the participation of all valid candidates that will appear on enough state ballots to have a possibility of winning the election. (Presently, 270 electors.)