Because she's on the bubble.
To understand why, you have to look beyond the raw numbers of the two latest polls, which were released just before Thanksgiving.
The first, by Southern Media and Opinion Research (SMOR) of Baton Rouge, showed Landrieu leading Republican challenger Suzie Terrell by a margin of 50.4 percent to 33.9 percent. The remaining 15.7 percent were undecided or would not state a preference. The SMOR poll was taken for WVUE Fox 8 News.
"It's crucial for Landrieu that she polls above 50 percent," says pollster Bernie Pinsonat. "However, our survey assumes equal turnout among white and black voters. That did not happen in the primary."
If the turnout is 10 percent higher among whites, says Pinsonat, Landrieu slips to around 48 percent and Terrell inches upward. The bigger the "differential" between white and black voters, the closer the race becomes.
Moreover, the SMOR poll shows Landrieu almost static among white voters since October. "She has remained in the mid-30s," says Pinsonat. "That's not bad, but it's not enough to give her a lot of comfort."
In the weeks before the Nov. 5 primary, Landrieu was polling around 35 percent among whites, Pinsonat says. In the survey released last week, she nudged upward slightly to 36.1 percent -- but that increase is statistically insignificant because the poll's margin of error is 4 percent. For Landrieu to show virtually no improvement among white voters since the primary is bad news for the Democrat. It means she not only will have to get 95 percent of the black vote on Saturday -- which likely will happen -- but she'll also have to get blacks to the polls in numbers proportionate to white turnout.
That won't be easy, but she's working on it.
Meanwhile, Terrell received 48 percent of the white vote in the latest SMOR poll, which is significantly higher than her showing in the primary.
With President George W. Bush coming to town this week to stump for Terrell, look for the GOP to pull out all the stops to go after what I call the "soft white middle." That is, moderate whites who voted for Landrieu last time over the "extreme" Woody Jenkins but who may be quite comfortable with Terrell, particularly after encouragement from the Prez.
Another poll released the same day as the SMOR survey was taken for WWL-TV News by Ed Renwick, director of the Loyola Institute of Politics. It showed Landrieu leading Terrell statewide by a margin of 45 percent to 31 percent, with the rest either undecided or refusing to pick either candidate.
Renwick factored in "leaners" to determine where the undecided vote might go, but the totals didn't change much: 48 percent for Landrieu to 33 percent for Terrell.
Here again, the pollster sees Landrieu having a tough time of it on Saturday. "An incumbent has to go over 50 percent" to feel good about her chances, says Renwick, adding that he expects the margin to be "paper thin" this weekend.
Renwick's survey for WWL also showed Landrieu not winning enough white votes to lock things up, even with overwhelming support among black voters. His survey had Landrieu getting 33 percent of the white vote to Terrell's 42 percent. In both surveys, Landrieu trounces Terrell among black voters.
For the last six years, Landrieu has worked her butt off trying to get to the middle. But, for some reason, she hasn't convinced many voters in Louisiana's middle that she's there yet.
That, in a nutshell, is why she's on the bubble.