Haley Barbour, former governor of Mississippi, former head of the Republican National Committee, says he first became seriously interested in immigration policy after Hurricane Katrina.Thousands of homes in Mississippi were destroyed, "down to the slab," Barbour said at a recent conference on immigration held by National Journal in Washington. Construction workers were overwhelmed; many were homeless themselves. And then, almost out of nowhere, came help."We were blessed with a huge influx of Spanish speakers, and I'm sure a lot of them weren't in this country legally," Barbour said.