And while the exit polls gave little insight into how Tuesday's election might play out - showing voters evenly split among the candidates, those who decided how they were voting recently tended to break for Rick Santorum and Mitt Romney, rather than Newt Gingrich. About a third of voters said they made up their minds in the past few days.

Two-thirds of voters in Alabama self-identified as Republicans, while 28 percent said they were independents and 6 percent were Democrats, the exit polling found.

As in the 2008 primary race, about 80 percent of Mississippi primary voters self-identify as Republican, with 17 percent calling themselves independent, and 4 percent aligning with Democrats.

Voters in Mississippi said that the top issue to them was nominating a candidate who could beat President Obama — and by a significant margin. The number of voters who put electability as their top choice nearly doubled those who voted based on experience, moral character or conservative values.