The attempt to end birthright citizenship wasn't really targeting Latinos (though of course it would have affected them) but more the "birth tourism" from Russia and China. In at least the case of China (not sure about Russia) this seems to be largely Chinese government sponsored which is concerning. I don't think trying to end birthright citizenship is necessarily the best way to combat that but something needs to be done. I don't think the supreme court decision in this case was shocking or even surprising.

As a side note, even if ending birthright citizenship had been upheld, it would not have been retroactive to those who already have citizenship. It would only have affected those intending to break the law (and of course the citizenship of their children). I believe that in most countries, citizenship is based on the citizenship of your parents.