Just as with the primaries being rigged the Establishment and Main Stream Media are now rigging the Presidential debates.
Instead of giving the stage to the "four" candidates running for POTUS the powers to be want to keep it just "two" which happen to be the candidates selected (at least partially) by the Establishment; Hillary and the Wild Card (Trump) they are still plotting to bring down.
So, what about the other 2 candidates; Stein (Green) and Johnson (Libertarian)?
Why keep them off the stage and national limelight?
Simply put; fear. The Establishment is afraid that a narrative they can't control could upset the apple cart if Main Street Americans (voter) were better informed and made aware that they do have choices besides the lesser of "two evils."
Commission on Presidential Debates announces polls to be used for securing spot - POLITICO