Rick Santorum has clawed back to within striking distance of Mitt Romney nationally, according to Gallup’s latest five-day rolling average.

Romney leads with 32 percent, followed by Rick Santorum at 27 percent, Newt Gingrich at 17 percent and Ron Paul at 12 percent.

Just over a week ago, Romney became the first candidate to surpass the 37 percent mark in the Gallup national poll, as he opened up a 16-point lead over the rest of the field.

That lead has essentially evaporated, and it’s not just Santorum making gains — as the Republican primary swings through the southern states, Gingrich has also seen his fortunes improve, picking up 5 percent over the last week.

Gingrich has staked his campaign on a “southern strategy,” as his only two victories to date have come in South Carolina and his home state of Georgia.

The candidates face off in critical primary contests in Alabama and Mississippi on Tuesday. Gingrich needs to outperform in both states to quell criticism from the Santorum campaign that he should drop out to allow for a one-on-one match-up between Romney and a viable conservative alternative.

Santorum also needs a strong showing, as a Romney victory in either state will signal to the party that his message is finally connecting with the base.

Polls show that both races are too close to call.

READ MORE: THE HILL