This isn't a war (cultural "war" notwithstanding), so under most circumstances no, they can't. And since the Oregon law this ruling is based on is unconstitutional then the gag order is illegal as well and in general flies in the face of the constitution. Free speech without consequence from government means exactly that, actually. You'd have an argument if the free market were forcing this on them; but it is the very government the constitution addresses when limiting powers as incorporated against the states. Lincoln suspended habeas corpus but do you expect a peacetime government to do that? Ludicrous. Bottom line: The Constitution protects free exercise of religion from state interference. Sexual orientation is not included in the 14th Amendment, which does incorporate the Bill of Rights against the states (along with other rights). There is a conflict and the states will lose to the feds every time. Congress has also carved no niche for sexual orientation and even if they did without a new Amendment it probably would not fly - and "probably" only because I don't expect the Constitution to always be followed even if it should.