Our judges have always held political views. As long as the legislature cannot interfere with the judges, they're still more or less immune from their oversight. I suppose it's theoretically possible for one party to control both houses, as well as the Executive branch, impeach all 9 justices, and pack the court, but that would be political suicide on SO many levels. The other party and the independents would scream bloody murder during the next election cycle. And neither party really wants to open the can of worms that precedent would set when the OTHER party has control of all three apparatus.
Truth be told, while I appreciate the court as currently constituted, a 3-3-3 breakdown maintained forever would tickle me pink... give me three liberal judges, 3 conservative, and 3 independent swing judges.