By Joan Biskupic, CNN Chief Supreme Court Analyst(CNN) — Justice Anthony Kennedy considered quitting the Supreme Court over abortion. Catholics have increasingly dominated the high court and prompted debate over how the justices’ faith influences their decisions. The court has also moved rightward on social policy issues imbued with a religious dimension, such as reproductive rights and LGBTQ rights. University of Virginia law professor Douglas Laycock, who has long focused on cases involving the First Amendment guarantees of religion, says people naturally wonder how the justices’ faith plays into their decisions. Kennedy writes in his book that he disliked being described as the court’s “swing vote,” but the centrist conservative constantly made the difference in important cases.