There is no text to hang a hat on when you are talking about a penumbra of implied rights.
The birthright citizenship issue comes down to an interpretation of "subject to the jurisdiction" ... modern vs. original. Just like the Second Amendment comes down to the meanings of "regulated" and "militia" ... modern meanings vs. original meanings. I honestly haven't explored the birthright citizenship issue as fully, so I'm not ready to commit to an interpretive basis (although the Left can't pretend that it isn't in the power of SCOTUS to decide that, when SCOTUS would be using Lefty constitional theory to get there...if the Constitution is a living breathing document as they say, they can't complain when an activist court breathes a way they don't like). I will say that birthright citizenship has served its purpose, and I would support a constitutional amendment to make citizenship a blood right, not a location of birth right. Again, I haven't thought it all through, but it seems that blood citizenship is a more reasonable approach given modern realities of people moving around. In many countries, our state department employees spend most of their time trying to keep pregnant mothers from booking tickets to the US. Seems like a waste of resources.