Advocates of instituting Islamic Sharia law in the United States are not protected by the Constitution's freedom of religion provisions.
Sharia law, in which a civil constitution is abolished and replaced by arbitrary interpretations of the Koran, is coercive political warfare. Advocacy of Sharia law by definition means advocacy of the overthrow of the Constitution - a political position, not a religious one. Due to Sharia's usually coercive nature, taking action to advocate the imposition of Sharia law in the US is therefore a crime in this country.
Such activity - even if expressed as verbally, with no direct political action - is a felony under the "treason" chapter of the US Criminal Code (Title 18, Part I, Chapter 115, Section 2385).
According to Section 2385, "Whoever knowingly or willfully advocates, abets, advises, or teaches the duty, necessity, desirability, or propriety of overthrowing or destroying the government of the United States or the government of any State, Territory, District or Possession thereof, or the government of any political subdivision therein, by force or violence, or by the assassination of any officer of any such government; or
"Whoever, with intent to cause the overthrow or destruction of any such government, prints, publishes, edits, issues, circulates, sells, distributes, or publicly displays any written or printed matter advocating, advising, or teaching the duty, necessity, desirability, or propriety of overthrowing or destroying any government in the United States by force or violence, or attempts to do so; or
"Whoever organizes or helps or attempts to organize any society, group, or assembly of persons who teach, advocate, or encourage the overthrow or destruction of any such government by force or violence; or becomes or is a member of, or affiliates with, any such society, group, or assembly of persons, knowing the purposes thereof—
"Shall be fined under this title or imprisoned not more than twenty years, or both, and shall be ineligible for employment by the United States or any department or agency thereof, for the five years next following his conviction.
"If two or more persons conspire to commit any offense named in this section, each shall be fined under this title or imprisoned not more than twenty years, or both, and shall be ineligible for employment by the United States or any department or agency thereof, for the five years next following his conviction.
"As used in this section, the terms 'organizes' and 'organize', with respect to any society, group, or assembly of persons, include the recruiting of new members, the forming of new units, and the regrouping or expansion of existing clubs, classes, and other units of such society, group, or assembly of persons." [Emphasis added]
It's time to start enforcing the law.