As I have said before, the Muslim Brotherhood is a Secret Society and not all of it’s Members are Public about their membership. It has been asserted that Khizr Khan isn’t a member of the Muslim Brotherhood because it hasn’t been proven and He hasn’t confessed that he is. Regardless, he is furthering the Will of the Muslim Brotherhood, he is an Islamist, he sympathizes with Sunni perspectives on Islam, and he is a Champion of Sharia Law.
But more than this, Khan is a promoter of Islamic Sharia Law in the U.S. He was a co-founder of the Journal of Contemporary Issues in Muslim Law (Islamic Sharia). Khan’s fascination with Islamic Sharia stems from his life in Saudi Arabia. During the eighties Khan wrote a paper titled Juristic Classification of Islamic [Sharia] Law. In it he elucidated on the system of Sharia law expressing his reverence for “The Sunnah [the works of Muhammad] — authentic tradition of the Prophet Muhammad (Peace be upon him).” (SOURCE)