Mississippi GOP Sen. Trent Lott, an ideological ally of future House Speaker Newt Gingrich, and South Dakota Democratic Sen. Tom Daschle, a moderate peacemaker, won election to key Senate posts today, each by a one- vote margin. Lott became Senate GOP Whip, unseating veteran Alan Simpson (R-Wyo.), incoming Majority Leader Robert Dole's right-hand man, and giving more conservative Republicans a strong grip on the Senate leadership. In winning thepost of Democratic leader, Daschle edged the more combative Christopher Dodd (D-Conn.), 24-23, suggesting a philosophical mismatch with a hard-line Democratic House minority under Rep. Richard Gephardt (D-Mo.), who was re-elected Wednesday.