BILOXI, Mississippi — It's been called the “nastiest primary in the country.” Now you can add allegations of “walking around money” and “vote buying,” a Democratic operative nicknamed “Scooby Doo,” and the testy denials of a Sen. Thad Cochran (R-MS) ally to the mix. Rickey Cole, the chairman of the Mississippi Democratic Party, says Cochran’s allies are paying Democratic operatives to help get out the vote with a questionable tactic. “Pete Pery” – the chairman of the Hinds County Republican Party – “is paying James ‘Scooby Doo’ Warren thousands of dollars to funnel to black preachers and others to get-out-the-vote...