LAS VEGAS — A Nevada rancher who became a conservative folk hero for standing up to the government in a fight over grazing rights lost some of his staunch defenders after wondering aloud whether blacks might have had it better under slavery.

WASHINGTON (AP) — A bipartisan effort to expand background checks was in deep trouble Wednesday as the Senate approached a long-awaited vote on the linchpin of the drive to curb gun violence. As the showdown drew near, an Associated Press-GfK poll showed ebbing public support for tightening gun control laws.