"A nominee's political ideology is only relevant if it has been shown to cloud their interpretation of the law. . . . A pattern of irresponsible judgment, where decisions are based on ideology rather than the law, could potentially be 'extraordinary.' "
Change "could potentially be" to "is" and you've nailed it.
Of course, we'll still have to argue over what counts as "clouded" and "irresponsible," and I'm going to withdraw my approval if it turns out to be just the view that the decisions produced by principled originalism or textualism are wrong. Tell me, Senator Landrieu: If you applied this standard to Justice Scalia or Thomas, would they deserve a filibuster? The answer should be no.