Rick Santorum’s trio of victories ...is shifting the Republican presidential contest into a state-by-state fight for delegates that could last much longer than initially anticipated. The battle appears to be breaking down along regional lines, with Santorum gaining momentum in the Midwest, Newt Gingrich resonating in the South and Mitt Romney faring best in the Northeast and elsewhere... For now, all four candidates are on a hunt for delegates, each with an incentive to stay in through the next several contests. Gingrich and Ron Paul were already pledging to stay in the race for the long haul, and both have...
