Bush's argument here is that gays should (grudgingly) not be discriminated against for their identity, but that it is okay to discriminate against their practice (in wanting to be married), both in terms of the law forbidding it or letting folk legally refuse services that are even peripherally related to a gay marriage.
As Stern notes, this is very different from his argument on religion, where he claims that Christians should certainly be protected based on their identity, but also protected in their practice of Christianity, whether that's going to church or refusing to bake cakes for gay marriages.
And that begs the the distinction between homosexuality (which is arguably something someone is born as) and Christianity (which is arguably something someone chooses to be).
Jeb Bush Accidentally Made a Brilliant Argument Against Anti-Gay “Religious Liberty” Laws
Jeb Bush has an odd conception of liberty. As governor of Florida, Bush strongly opposed same-sex marriage, preferring to force committed gay couples to live as legal strangers with no ability to formally adopt their own children. As his presidential campaign warms up, though, Bush has taken a selectively expansive…
