Midterm Elections 2014: Louisiana Senate Race Will Go to a Runoff

— -- The Louisiana Senate race is heading into a December run-off as no candidate was able to secure 50 percent of the vote.

Based on preliminary exit polls, ABC News projected Sen. Mary Landrieu, D-La., will face-off against Rep Bill Cassidy, R-La., in the run-off.

Campaign committees and outside groups have already reserved airtime ahead of an expected run-off. The National Republican Senatorial Committee has set aside $3.3 million to run ads in the month ahead of the December run-off. The Koch-backed group FreedoM Partners has also reserved $2.1 million in television advertisement time ahead of an anticipated run-off in the Bayou State.

National Exit Poll Reveals Major Voter Discontent

PHOTOS: The Unusual Places Where Americans Vote

Here’s everything you need to know about what happens next:

When will we know the winner?

The runoff election to determine the ultimate victor in the race is scheduled for Saturday, Dec. 6.

Why is this happening?

Louisiana has a unique non-partisan "jungle primary" electoral system, meaning that all candidates run on the same ballot on November 4 instead of holding separate party primaries in advance of the general election. The rules of the “jungle primary” dictate that if no one candidate receives over 50 percent of the vote in the general election, the two candidates with the most votes advance to a runoff election.

This race was expected to go to a runoff due to the presence of second Republican candidate, tea party favorite Col. Rob Maness, who touted the endorsement of former vice presidential candidate Sarah Palin.

What did today tell us about what will happen in the runoff?

Though the final outcome of this race remains ambiguous, Louisiana voters have gained some clarity in that they can now focus on just two candidates, Landrieu and Cassidy. But that’s just about where the clarity ends and uncertainty begins again.

Polling in advance of today’s election has indicated that Landrieu is likely to lose in a runoff scenario against Cassidy. A recent NBC/Marist poll, released just days before today’s election, showed Landrieu losing to Cassidy by a slim margin 5 percent margin, 45 to 50 percent, respectively. Polling aside, runoffs in Louisiana can be unpredictable. A lot can change in a month.

While Cassidy will likely pick up many of the voters who went with Republican alternative Rob Maness in the general election, the runoff may also inspire new voters who sat out the general election to make their voices heard.

What does history tell us?

Runoffs are familiar territory for Sen. Mary Landrieu. Of her three previous Senate elections, Landrieu has won two through runoffs. Now the question is: Can she manage a third?

Landrieu’s first Senate race in 1996 was won in a runoff by a margin of less than 6,000 votes. But it was her reelection victory in 2002 that sealed her reputation as a runoff survivor.

The 2002 midterms were characterized by a wave of Republican victories at a time when then-President George W. Bush enjoyed broad popularity. Republicans had already captured a Republican majority in the Senate before the Louisiana runoff and expected Landrieu’s opponent, who benefitted from President Bush’s endorsement, to pick up the seat. But following a revamped ground game, Landrieu managed a runoff surprise and retained her seat in the Senate.

In 2008, Landrieu benefitted from the Obama wave that brought historic levels of black voters to the polls and avoided a runoff scenario altogether.

What’s different today?

Few comparisons can be drawn between Landrieu’s 2008 victory and the situation she faces in 2014. If President Obama was Landrieu’s ticket to victory in 2008, he is her liability in 2014. Landrieu has made every effort to distinguish herself as an independent from President Obama in this election, while defending her vote for what she calls “an imperfect” healthcare law and a record of voting with the president 97 percent of the time.

While emphasizing her independence, Landrieu has simultaneously had to walk a careful line not to draw distance from her core base of Democratic-leaning black voters, whom remain more loyal to the president than other groups of the electorate. In a televised debate, Landrieu said she’d give President Obama a “6 to a 7,” when asked to rank him on a scale from 1-to-10. And just yesterday, First Lady Michelle Obama released a web video endorsing Landrieu.

It’s also worth noting that Louisiana has grown increasingly red since Landrieu first came to office 18 years ago, a change that was hastened by the exodus of some of the state’s black population following Hurricane Katrina in 2005. Landrieu is currently the only Democrat left standing in the state’s statewide delegation.

How much is this thing going to cost?

If control of the Senate is still hanging in the balance after tonight, the sky is the limit when it comes to campaign overtime spending in Louisiana.

Reports indicate that both Republican and Democratic campaign committees have prepared their respective war chests for a runoff, having already set aside approximately $5 million in advertising time, with outside groups having reserved almost $6 million.