The repeated thud-thuds you heard were the wheels of the bus -- driven first by abortion-rights advocates Emily's List. Then by former U.S. Rep. Harold Ford Jr. and then presidential contender Barack Obama himself, all rolling over congressional wannabe Nikki Tinker, who is a black woman. Her offense -- and it was an especially stupid one -- was tasteless attack ads. One linked U.S. Rep. Steve Cohen, a white, Jewish man, to the Ku Klux Klan. (Doesn't she know the Klan hated Jews just as much as black folk?) The other ad charged Cohen was voting against prayer in school...