So if a Segregationist Church were to hold it's ceremonies in it's own building and members of another race show up and, through thier presence alone, disturb the otherwise peaceful congregation - the church has no recourse but accept?
I think not.
This is exactly, precisely, identically, the same thing as enforcing Jim Crow laws
Denying a group access to facilities / businesses that serve the general public (bars, restaraunts, buses etc ...) can not be justified as no persons personal beliefs / liberties are infinged upon by allowing blacks, hispanics, etc ... access. That has nothing at all to do with forcing a religious group to accept persons it deems uncapable of worship access to it's sanctums.
Regards
‘Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof;’ Congress shall not, states may. DC is under the jurisdiction of Congress. The DC cops were prohibiting the free exercise of religion unconstitutionally!