This episode's headline: Setting Limits?; State of the Union; Newsmaker. ANCHOR: JIM LEHRER; GUESTS: REP. DICK ARMEY, House Majority Leader; SEN. THOMAS DASCHLE, Senate Minority Leader; DORIS KEARNS GOODWIN, Presidential Historian; MICHAEL BESCHLOSS, Presidential Historian; HAYNES JOHNSON, Journalist/Author; WILLIAM BENNETT, Former Reagan/Bush Cabinet Office; WARREN CHRISTOPHER, Secretary of State; CORRESPONDENTS: MARGARET WARNER; KWAME HOLMAN;