WASHINGTON – As the Senate prepares to begin debating new gun control measures, some of President Barack Obama's fellow Democrats are poised to frustrate his efforts to enact the most sweeping limits on weapons in decades.

These Democrats from largely rural states with strong gun cultures view Obama's proposals warily and have not committed to supporting them. The lawmakers' concerns could stand in the way of strong legislation before a single Republican gets a chance to vote "no."

"There's a core group of Democratic senators, most but not all from the West, who represent states with a higher-than-average rate of gun ownership but an equally strong desire to feel their kids are safe," said Mark Glaze, director of Mayors Against Illegal Guns. "They're having hard but good conversations with people back home to identify the middle-ground solutions that respect the Second Amendment but make it harder for dangerous people to get their hands on guns."