On the eve of a Southern showdown, Mitt Romney conceded Friday he’s in a tight race with Newt Gingrich for Saturday’s South Carolina primary in a Republican campaign suddenly turned turbulent.

It’s “neck and neck,” Romney declared, while a third presidential contender, former Sen. Rick Santorum, swiped at both men in hopes of springing yet another campaign surprise.

Several days after forecasting a Romney victory in his state, Sen. Jim DeMint said the campaign’s first Southern primary was now a two-man race between the former Massachusetts governor, who has struggled in recent days with questions about his personal wealth and taxes, and Gingrich, the former House speaker who has been surging in polls after a pair of well-received debate performances.