A new poll from the National Republican Senatorial Committee (NRSC) shows Landrieu leading Rep. Bill Cassidy (R-La.) by a narrow 45 percent to 41 percent, while one released from the outside GOP group Conservative Intel finds her trailing Cassidy by 47 percent to 45 percent.

Partisan polls should always be viewed a bit skeptically, but these two indicate what many have long believed: Landrieu faces a difficult reelection campaign in the conservative, Republican-trending state. There has been little public polling of the race so far.

President Obama is very unpopular in Louisiana: The NRSC poll finds his approval rating at 37 percent, with 59 percent viewing him unfavorably. But Landrieu's own numbers have held up: In the Conservative Intel poll she sits at a 44 percent approval rating with 37 percent disapproving, a decent spot for a Democrat in such a red state.

Neither poll is structured like the actual election, however. All candidates will be on the ballot at the same time, including Tea Party-backed Rob Maness (R), and there's a fairly likely chance the race will head to a runoff.

The NRSC poll was conducted by OnMessage Inc. from Aug. 13-15 and has a margin of error of plus or minus 4 percent. The Conservative Intel poll of 596 likely voters was conducted by Harper Polling from Aug. 14-15 and had a margin of error of plus or minus 4 percent.