At least two recent incidents in which empty chairs were hung from trees by rope have critics decrying what they say are racially offensive displays meant to symbolize the “lynching” of President Barack Obama. In Austin, Texas, a homeowner hung an empty folding chair from a tree branch in front of his house and later attached an American flag to it. He reportedly told a Democratic political blogger who inquired about it: “You can take [your concerns] and go straight to hell and take Obama with you.” In Centreville, Va., an empty chair with a sign reading “Nobama” was strung...