Why don't Conservative groups focus energy on using the conservative Supreme Court to kill the liberal agenda?

There is not a true majority of conservatives on the Supreme Court. Often there are four votes, which is not enough to win consistently. And, uming Obama will be in for eight years, the conservative's chances at the court are fading. Surely the "liberal" justices will retire first, but they aren't liberals; they are moderates and they will be replaced by liberals. There is no way Scalia will be alive in 8 years; when he is gone, the revolution is over. Social conservatism has no meaningful voice in our government. The culture war is wrapping up and the conservatives lost.