https://en.wikipedia.org/wiki/Commission_on_Presidential_Deb...
Multiple lawsuits have been filed by third-party candidates challenging the CPD's policy of requiring a candidate to have 15% support in national polls to be included in presidential debates. While the lawsuits have challenged the requirement on a number of grounds, including claims that it violates Federal Election Commission (FEC) rules and that it violates anti-trust laws, none of the lawsuits has been successful.