A parallel policy, applied to race, would be that you can be black as long as you don’t have sex with other blacks. Technically, the MSM exclusion isn’t a gay exclusion: You can be gay as long as you don’t have sex with other men. Is race a less legitimate basis for exclusion than sexual orientation is? Race is immutable, but plenty of evidence suggests that homosexuality is immutable, too. A similar calculation, applied to blacks, would yield a similar result. Accordingly, “to err on the side of safety,” MSM are excluded. “Several scientific models show there would be a small but definite increased risk to people who receive blood transfusions if FDA’s MSM policy were changed,” it notes. The agency says its job is to “ maximally protect” blood recipients. Under FDA doctrine, even slight differences in average risk are sufficient to warrant group exclusions.