Louisiana voters are deciding their choice for the Republican presidential candidate. Rick Santorum is leading Mitt Romney by double digits in recent polls in the conservative state.

Santorum is waging an uphill battle for the nomination against Romney, who leads in convention delegates by a margin of more than 2-to-1. Santorum hopes to keep Romney from reaching the 1,144 delegates needed to clinch the nomination before the nominating contests end in June.

Republican presidential candidate, former Pennsylvania Sen. Rick Santorum speaks at the AFP Defending the Dream Conference in Milwaukee, Wis., Saturday, March 24, 2012. [CNTV via agencies]

That would leave the choice up for grabs heading into the August convention in Tampa, Florida.

The next showdown after Louisiana will be Wisconsin on April 3rd, which is voting that day, along with Maryland and the District of Columbia.