David Goldman, Associated Press
Former House Speaker Newt Gingrich, center, watches election returns from a hotel room with wife Callista, right, and daughter Jackie Gingrich Cushman, left, before his Alabama primary night rally Tuesday, March 13, 2012, in Birmingham, Ala.

BIRMINGHAM, Ala. — Presidential candidate Newt Gingrich is vowing to stay in the GOP primary race despite losing two Southern conservative strongholds.

Gingrich is telling his supporters in Birmingham, Ala., that he will continue on to the Republican National Convention this summer.

His campaign had placed a premium on winning Tuesday's primaries in Alabama and Mississippi. But rival Rick Santorum has won both.

Gingrich says that rival Mitt Romney's case for being the inevitable nominee has been crippled by his failure to win the two Deep South contests.

Gingrich says his campaign's major issue of lower gas prices has resonated with Americans and has put pressure on the White House for cheaper energy. The former House speaker insists he is the best candidate to beat President Barack Obama in the general election.