What they call "extremists" are really just strict constructionists very much moderate considered in the context of broader American judicial history. Use of that term by liberals is a ploy.
Everybody uses political labels today. It's the thing to do.
Standard propaganda tactics. There are still a few stubborn holdouts who will recognize it for what it is and make a conscious attempt to refrain from engaging in it. To quote Rush "Words mean things." Throwing around labels that can't be objectively justified isn't helping. This is our government, not Sweeps Week.