WASHINGTON (AP) — Congress' most serious gun-control effort in years cleared its first hurdle Thursday as the Senate pushed past conservatives' attempted blockade under the teary gaze of families of victims of December's Connecticut school shootings. The bipartisan 68-31 vote rebuffed an effort to keep debate from even starting, giving an early victory — and perhaps political momentum — to President Barack Obama and his gun control allies. Four months after 20 first-graders and six staffers at Sandy Hook Elementary School in Newtown were killed, relatives watching the vote from a gallery overlooking the Senate floor dabbed at tears and clasped hands, some seeming to pray.