In Assassins, the Stephen Sondheim musical, everyone from John Wilkes Booth to John Hinckley Jr. gets a chance to explain themselves: Some are driven by insanity, some by politics, some by a desire to be remembered. Their motives and circumstances vary, but their common bond is that they all grasped for power by taking shots at some of the most powerful men on earth. The cast members of Assassins face the exhausting task of identifying with killers and trying to convince the audience to take their side. by Matt Baume