We're talking about protected classes here, and I don't think it's equally unacceptable. On a fundamental level, inherent characteristics (race) are very different from ideas (speech). So I think you can be in favor of anti-discrimination on basis of who you are, while also being against beliefs becoming a protected class.

Though, just so you know where I'm coming from, in my ideal world it would be strong social and business pressures that enforced the idea of protected classes, not regulation. I'd support any competitor which was more ethical, but complex issue.

The heritability of certain political preferences are higher than the heritability of homosexuality (a protected class).