Protect the National Security Council From Political Interference Act of 2017 This bill amends the National Security Act of 1947 to prohibit the President from designating any individual whose primary or predominant responsibility is political in nature to serve as a member of the National Security Council (NSC) or to regularly attend or participate in NSC meetings or meetings convened under the auspices of the NSC, including Principals Committee meetings. Organized under presidential memorandum, the Principals Committee is a cabinet-level senior interagency forum chaired by the National Security Advisor or the Homeland Security Advisor to consider policies that affect U.S. national security interests. The bill expresses the sense of Congress that no limitations should be imposed on the ability of the Director of National Intelligence or the Chairman of the Joint Chiefs of Staff, or their designees, to attend any Principals Committee meeting convened under the auspices of the NSC or any other senior interagency meeting convened to consider policy issues that affect U.S. national security interests.