The major super PAC backing Mitt Romney is once again dumping huge sums of money into the upcoming primaries and caucuses.

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In the past week, the PAC has reported more than $6 million in expenditures, more help than all the other candidates in the race are getting combined. But the PAC’s leaders, mostly veterans of Romney’s 2008 campaign, are already preparing for a GOP nominating race that extends past the 10 states that vote on Super Tuesday, March 6.

To date, the Restore Our Future super PAC has spent nearly $1 million in Alabama and more than $500,000 in Mississippi, two southern states that hold their primaries on March 13, according to Federal Election Commission records.

Both are states in which the former Massachusetts governor faces a competitive race against former senator Rick Santorum (R-Pa.) and former House speaker Newt Gingrich (R-Ga.), both of whom have proved popular among southern conservatives.

With Romney not exactly a natural fit in the Deep South, why would it make sense for his supporters to spend money there?

It all comes down to delegates.

In Alabama, if one candidate wins 50 percent of the statewide vote, that candidate gets all of the state’s at-large delegates; the same holds true for the state’s seven congressional districts. That means that for the Romney camp, preventing either Gingrich or Santorum from getting too strong a footing in the state is key.

Mississippi’s 40 delegates are awarded proportionally, so the greater share of the vote Romney is able to get there, the more delegates he’ll net.