Republicans Prepare Campaign War Chest for 'Overtime' in Louisiana Senate Race

If you think election season doesn't go on for long enough as it is, get ready for some overtime.

Television viewers across most of the country can take comfort knowing that political TV ads will pass with Election Day on Nov. 4. But that's not the case for Louisiana, where people can expect the airwaves to be pounded with aggressive political advertising for a full month after November's Election Day.

That's because the outcome of the Louisiana Senate race may not be known until December thanks to the state's unique jungle primary system. In a race that could determine control of the Senate, incumbent Democrat Sen. Mary Landrieu is locked in a tough bid for reelection against two Republican challengers and is expected to go to a runoff against her leading Republican challenger, Rep. Bill Cassidy.

Republicans are actively bracing for the likely scenario by setting aside money in their war chest to be used during the period after the general election in the lead-up to the runoff, ABC News has learned.

The National Republican Senatorial Committee has already reserved nearly $3.4 million to spend on the political TV ads between Nov. 6 and Dec. 6, an NRSC official confirmed.

In Louisiana's jungle primary electoral system, known more formally as a non-partisan primary, all candidates seeking an elected office run against each other on one ballot in the general election instead of having party primaries to decide on one candidate for each party. If no candidate receives more than 50 percent of the vote, the top two candidates advance to a runoff election on Dec. 6.

An NRSC official told ABC News the group's reserved funds are part of a strategy to support Cassidy in his race against Landrieu.

There is a second Republican challenger, tea party favorite and political newcomer Rob Maness, but he is not expected to pose a real threat to either candidate, though his presence in the race does increase the probability that the race will go to a runoff.

The NRSC official argued that the Democrats' spending in the race tells a more interesting story, one that signals "panic over going into a runoff."

According to information collected by the NRSC's media buyer, the Democrats have set aside $7.9 million to spend in the lead up to the general election, compared to the Republicans' $3 million.