Whoever’s elected president today -could- appoint as many as four new justices to the U.S. Supreme Court. Scott Peters, a political science professor at the University of Northern Iowa, says eight of the nine justices are over the age of 65 and Chief Justice William Rehnquist just announced he has thyroid cancer. Peters says most presidents get about two appointments every four years, but there haven’t been any new justices since 1994, so several resignations are likely over the next four years. New appointments to the nation’s high court could swing the balance of power, depending on who steps down and who wins the presidency. In recent years, there have been five-to-four decisions on several key debates including gay rights, abortion, education and affirmative action. Peters says the battle over control of the U.S. Supreme Court is usually reserved for the very liberal or very conservative voters, not the mainstream.Peters says people who care about the high court’s balance of power already chose their presidential candidate months ago, so the announcement about Rehnquist’s illness likely will not effect the election’s outcome.