WASHINGTON (AP) -- Determined to challenge President Bush, Senate Democrats are drafting legislation to limit the mission of U.S. troops in Iraq, effectively revoking the broad authority Congress granted in 2002, officials said Thursday. While these officials said the precise wording of the measure remains unsettled, one draft would restrict American troops in Iraq to combatting al-Qaida, training Iraqi army and police forces, maintaining Iraq's territorial integrity and otherwise proceeding with the withdrawal of combat forces. The officials, Democratic aides and others familiar with private discussions, spoke only on condition of anonymity, saying rank-and- file senators had not yet been...