He's a Romney spoiler down south.

The Huckabee factor may be getting relatively little attention nationally in the Republican nomination battle because the former Arkansas governor has failed to repeat his Iowa victory. But in a region that has equal or greater evangelical strength than Iowa, Huckabee may become the decisive factor - at Romney's expense.

Voters identifying themselves as evangelicals and Christian conservatives could make up more than half of the Republican electorate in the four Southern states voting Tuesday, analysts said. The contests - out of 21 across the country - are being held in Huckabee's home state of Arkansas as well as Alabama, Georgia, and Tennessee.

--Michael Crowley