Santorum, Gingrich duke it out down south

This week’s Southern primaries are shaping up as make-or-break contests for Republican presidential contenders Rick Santorum and Newt Gingrich, who are battling to become the lone conservative alternative to front-runner Mitt Romney.

Gingrich, who won two Southern primaries but trailed Romney and Santorum in every other contest, knows the stakes could not be higher in Tuesday’s primaries in Mississippi and Alabama. His own campaign aides acknowledge that the former House speaker must win both states to remain a credible contender.