Barack Obama might have as much power to shape a new court as Reagan. Like Reagan, Obama could appoint as many as three justices before Inauguration Day 2013. John Paul Stevens, 88, and Ruth Bader Ginsburg, 75, are of retirement age, and Ginsburg is a colon cancer survivor. David Souter, 69, has reportedly expressed an interest in returning to his home in New Hampshire. (Kennedy, who has twice had minor heart procedures, is 72, as is Scalia.)