Have that independence and supremacy been abused? Grossly. What other advanced democracy would radically legalize abortion by judicial decree rather than by democratic will expressed through legislatures or referendums? What sane democracy allows four unelected robed eminences in Massachusetts to revolutionize the very definition of marriage, the most ancient institution in society?
Obviously, no nation other than the United States would allow robed eminences in Massachusetts to make decisions about the legality of discrimination on the basis of sexual orientation in marriage, but provincial Supreme Courts in such far-off lands as Canada have likewise been ruling on such matters. And if you want to know what other advanced democracy would have judicial decrees legalizing abortion you, again, don't need to look further than Canada. All of which would merely demonstrate ignorance on Krauthammer's part were he not, well, Canadian.