Supreme Court CJ Roberts sometimes disappoints conservatives

Supreme Court Chief Justice John Roberts is not as solidly conservative as his 3 conservative colleagues (Alito, Scalia and Thomas), disappointing them and conservative court-watchers.  Roberts joined with the conservatives in the Court's last 2 hot-button decisions and in Citizen's United.  However, his vote in favor of Obamacare shocked and surprised many.  One theory is that he is trying to move more toward the ideological center to become a more effective leader and  keep the institution from becoming too one-sided.  See this excellent article from the WSJ.