It's well established that any seperation of church and state only applies at the federal level. States are supposed to be able to do whatever they want.
If "states supposed to to be able to do whatever they want," what is to prevent them from establishing a religion, or to give preference to one religion over another?
States have their own constitutions which set the parameters. Some states (like Texas) are stricter than the U.S. constitution in protecting against discrimination.