This episode's headline: Assisted Suicide; Madam Secretary; School for Scandal. ANCHOR: JIM LEHRER; GUESTS: STUART TAYLOR, The American Lawyer; DR. MARCIA ANGELL, New England Journal of Medicine; DR. IRA BYOCK, American Academy of Hospice and Palliative Medicine; SUZANNE GARMENT, American Enterprise Institute; MICHAEL BESCHLOSS, Presidential Historian; DORIS KEARNS GOODWIN, Presidential Historian; HAYNES JOHNSON, Journalist/Author; CORRESPONDENTS: ROD MINOTT; ELIZABETH FARNSWORTH; MARGARET WARNER; KWAME HOLMAN;