WASHINGTON (AP) — President Barack Obama's request for congressional backing to train and arm rebels battling Islamic State militants in Syria is halfway home after its easy approval by the GOP-controlled House sent the issue to the Senate, where leaders in both parties say approval is ensured. Top leaders of both parties stood with the president despite reservations that his strategy of arming moderate rebel groups could backfire or won't be enough to blunt the advance of Islamic State forces. The Senate was to vote Thursday on the measure, which was added to a must-pass, stopgap spending bill to keep government agencies operating into December. GOP hawks called the president's approach too little, too late, even as many of them supported it as a first step in a broader campaign against Islamic State extremists, who have taken large swaths of Iraq and Syria and shocked the world by beheading two American journalists and a British aid worker. The underlying spending bill prevents a government shutdown at month's end and also renews the charter of the Export-Import Bank, which helps finance purchases of U.S.