Chuck Grassley actually said...

Well, the decision involved the Fourteenth Amendment that was ratified, as you know, back in 1868, and the case was decided in 1972.

So based on Baker v. Nelson, using your words, it's not really settled law, even though a one-sentence statement as precedent, it says 'the ...

No court should make or justify its decisions solely by reference to the demands of social justice.

I know the Declaration of Independence is not the law of the land, but it does express the philosophy of why we went to war.