Living constitutionalism doesn't quite make sense to me, insofar as it means that the constitution means whatever we want it to say, which results in it not act

Living constitutionalism doesn't quite make sense to me, insofar as it means that the constitution means whatever we want it to say, which results in it not actually being a check on the government's powers. This isn't to say there isn't some ambiguity in the constitution, and that ambiguity can be beneficial. But the living constitution theorists tend to read more ambiguity in than actually exists. This includes saying things like: constitutional review didn't exist until Marbury v Madison. This ignores that it was a thing under the various state constitutions, with it not being called out specifically, and that it falls naturally under the fact that SCOTUS has the power to decide all cases and controversies, and Stare Decisis combines with that to say that if SCOTUS decides one way on a constitutional issue, they'll continue to decide the same way on that issue, so if a lower court judge decides the other way, they'll get reversed when it gets appealed, probably summarily in a one line opinion of the Court.