BIRMINGHAM, Ala. (AP) — Deep South primaries today could answer questions for all three Republican presidential candidates.

Polls are open in Alabama and Mississippi as Mitt Romney tries to make a southern breakthrough. At the same time, Newt Gingrich is seen as needing wins to stay in the race while Rick Santorum looks for a knock-out blow against Gingrich. Santorum wants to go one-on-one with Romney.

It appears to be an unexpectedly tight race in the conservative bellwether states.