...."I have had grits before," he told a crowd at a Mobile cafe on Saturday morning, making a not-so-subtle knock on former Massachusetts Governor Mitt Romney's joking admission to an audience that he was starting to like the favorite Southern food. ....The former House Speaker contended that was evidence of a larger problem facing his rival: "I figure if you don't understand grits, there's a pretty high likelihood that you don't understand the rest of the South, either." ...."We have momentum, but we haven't won," he told a crowd at his second cafe stop of the day - Mama Lou's...