Mitt vs. Newt: Establishment vs. Grass Roots Insurgency

South Carolina demonstrated there's no real front-runner in the GOP race for the Republican nomination. Maybe there never was. Newt Gingrich now leads Mitt Romney in Florida polls with nine days left until the next primary and with candidates raising the rhetorical volume before tonight's 18th debate in Tampa. Gingrich is still calling Romney a "Massachusetts liberal" and, in a message to voters old enough to remember Gingrich as House Speaker, Romney says Gingrich "had to resign in disgrace." Rick Santorum and Ron Paul are still nipping away, but how much longer can this go on, as establishment Republicans try to cope with right-wing populism?