So many different races and religions that it's best to stick to good old secularism.
How does race come into it at all? Religion is about belief and most religions welcome people of any race.
Non theistic Buddhism is still considered a religion.
Worldview might be a better term for us to use in understanding people's first amendment rights. And also the idea that there is no neutral worldview. E.g. "secularism" is directly hostile to many religious viewpoints, and to the degree that its proponents use it to oppose religion, secularism becomes a religion/worldview/belief system.