Islamic supremacy, if implimented globally very slowly, incrimentally, over time, will be a danger to America's freedom and, of course, the entire world. One Islamic supremacist group in America which came out of the shadows after Obama was elected is Hizb-ut-Tahrir. Observe the screen shot I took of their video which shows an Obama 2012 ad that popped up during their trailer for the 2011 Khilafah conferenc! Last year, their Khilafah Conference never happened but it did in 2009. This year they either are keeping the location of the conference under wraps or haven't secured a location. The date of it is June 26th.
A caliphate or khilafah is an Islamic supremacist leader which rules over other using a sharia-based ruling system.