On a 2008 episode of the Point of Inquiry podcast, civil rights attorney Edward Tabash touched on an issue that, to me, resonated well beyond beyond the Prop 8 topic he was discussing.

If people with a religious motive can appeal to bogus junk science to get around the church-state issue, then church-state separation has been nullified. So, let me elaborate. So if somebody says, "Well, I'm not trying to restrict gay rights because of any religious belief, but these scientific studies show these psychological problems with gay men, or show these psychological problems with women who've had abortions," then what they are doing is using pseudo-science to try to create a bogus - but smokescreen alternative - to their true religious motive, and they've made an end run around church-state separation. So that is the danger. If we have pseudo-science, and you say, "You cannot base your law on religion, you have to have an empirical study", and they have a bogus scientific study, what they have done is that they have done a devious end run around church-state separation by bootstrapping fake science into some kind of fake - but possibly passable - secular justification for what's really a religious motivation.

I remember someone once arguing with me that they read a study that showed that most sex offenders have looked at pornography, so therefor, pornography makes people become sex offenders. That line of reasoning makes total sense- but only if you're grasping at straws to justify your unflinching moral beliefs (whether or not those moral beliefs are directly based on a religion). I bet most sex offenders also enjoy masturbation, but that doesn't mean that rubbing your happy places turns you into a rapist.

"Junk science" is used by many different kinds of groups trying to make their religious/moral message appeal to wider audiences. Don't let people do an end-run around logic by throwing in the words "study" or "research".