Who rules supreme in America?

Within hours of Supreme Court Justice Ruth Bader Ginsburg’s death, Democrats and Republicans began fighting over how to fill her seat — and when. The stakes are high because the Supreme Court is so important. It can invalidate any federal, state or local law by ruling that it violates the US Constitution. And its decisions set precedents that lower courts must follow. Its rulings are final, made by judges with lifetime appointments.

Donald Trump intends to fill Ginsburg’s seat as quickly as possible. He will announce his nominee by the end of the week. That nominee will then face hearings before the Senate Judiciary Committee, chaired by the Republican Lindsey Graham. Once a nominee gets through the committee, the full Senate debates his or her case. Given recent history, and the looming presidential election, it’s hard to exaggerate just how contentious this process will be.

These days, nominees need only a simple majority.