WASHINGTON (AP) — Facing off in one of the most contested Senate races in the nation, Colorado Democratic Sen. Mark Udall and his Republican challenger, Rep. Cory Gardner, found something to agree on this week — giving President Barack Obama the authority he's asked for to train and arm Syrian rebels taking on brutal Islamic State militants. Polls show the public supports a forceful response against Islamic State fighters who've taken over portions of Iraq and Syria and beheaded two American journalists and a British aid worker. Some lawmakers said Obama's strategy wouldn't succeed in defeating the militants, and there was little appetite among war-weary voters for an open-ended commitment or the involvement of American ground troops — something Obama promised would not happen. The legislation giving Obama authority to train and arm Syrian rebels passed the House 273-156 Wednesday and the Senate was expected to take it up Thursday. Senate leaders were combining the measure with must-pass legislation to fund the government into December instead of holding separate votes as happened in the House, which could help some lawmakers cast — and explain— a "yes" vote. Earlier this summer, Democratic Sen.