IOW, I may not subscribe to Christian nor Jewish beliefs, but feel there is a way to peacefully coexist with them in a 21st century democracy.
I would classify as sect any religious belief that does not allow for long-term, peaceful coexistence with non-believers, and does not allow its members to freely and without reprisal abandon the faith unconditionally. While a healthy democracy requires us to be open-minded and accepting of major differences, I see no contradiction in being intolerant of an aggressive sect, such as Islam, that openly preaches the antithesis of the cherished ideals that underlie democracy.
Not only would I say "no mosque at ground zero," but also no protection under the law as religion of any teaching that does not allow, indeed forbids, peaceful coexistence with nonbelievers. The right to freedom of religion (conscience) must be understood as equally guaranteeing freedom *from* religious coercion.