The latter, but it's always been the latter. But usually they've been better at using the former to hide the latter. Recently, there's been a much thinner veneer of "legal principles".
In general, I find the concept of originalism to meet this criteria. Especially as originalist justices are turning to tradition over originalism. The bend from "the words as originally written" to "our traditions" is a fundamentally conservative (lowercase c) one.
In cases like Vidal v. Elster, United States v. Rahimi, and Samia v. United States I think you'll see the justices straining to understand how how square originalism against the modern world, and having to turn to another justification, traditionalism, which feels more like a "I believe this to be true, due to my political lenses" than perhaps some originalist justices in the past.
That said, I personally find originalism to be pretty conservative already (lowercase c again), and kind of silly, but the recent justice appointments are dialling it up more and more.
Lol, that's what conservatives think about Sotomayor and Jackson, and looking at their comments during oral arguments as well as their opinions, I think they have a point. (Kagan is generally a more rigorous thinker.) Actually most cases argued before the Supreme Court still have a unanimous or almost unanimous outcome, or are denied cert (which would often indicate a unanimous opinion were it to be ruled upon). It's only in the more controversial cases where you're more likely to read the more blatantly political arguments.