I really wish people would stop trying to compare gays to black people. They are not the same. First, the civil rights act is a law, not a constitutional provision. It is enabled due to the 14th amendment powers in section five in order to enforce section one of the same. Congress has chosen not to include gays within the class of protected persons. Second, congress uses the interstate commerce clause in order to apply the civil rights act to certain businesses large enough or operating across state lines. Finally, congress has declared that in order for the 14th amendment to be enforceable, an even smaller set of businesses not covered by the interstate commerce clause that provide public accommodations would have to comply to ensure the 14th amendment powers can be effective.
While you can certainly make the case that congress should include gays as a protected person (or class of people ), you also have to look at the 9th and 1st amendments which prohibits government from prohibiting the free exercise of religion and states that no right or privilege enumerated shall be used to deny rights or privileges held by the people. So in essence, a constitutional amendment would likely need to be made to square any conflicts that would prevent the free exercise of religion. Laws do not override the constitution.
So gays are not remotely the same as blacks legally or constitutionally when it comes to protections. And it varies from state to state as to if their civil rights legislation does include gays, but that would be a state rule which wouldn't override the constitution.