The greatness of the American experiment (so far) has been that, while America is a majority Christian nation, it is fundamentally a pluralistic one that has made room for all religions and those who profess no religious affiliation at all.

As a Christian, I don't want a Muslim telling me what I ought to believe any more than I want the late Jerry Falwell or his Trump-supporting son telling me what I ought to believe. The fact that we've made room for everyone to believe in whatever or whomever they want or nothing at all is our greatest strength as a country. 

Why anyone, religious or otherwise, would want to trade that in for a terrifying theocracy like Iran or Saudi Arabia, a moribund state religion on life support like Anglicanism in England, or a stultifying atheism as existed in communist China, is beyond me.