Updated

Embattled U.S. Rep. William Jefferson hunted for votes among churchgoers Sunday as he headed into the final week of a campaign to hold onto his seat and salvage his political fortunes.

FBI raids on his homes and his congressional office, including allegations in an FBI affidavit that he hid $90,000 in bribe money in a freezer, have left Jefferson vulnerable for the first time since he won the seat in 1990.

In the Nov. 7 open multiparty primary, the Democratic congressman netted 30 percent of the vote, considered a poor showing for an incumbent.

In Saturday's runoff, Jefferson faces a stiff challenge from state Rep. Karen Carter, a Democrat and well-financed and energetic lawyer hoping to become the first black female from Louisiana to ever hold a seat in Congress. The runoff is one of the nation's last unresolved elections.

Carter, 37, who picked up 22 percent of the vote in the primary, has outpaced Jefferson handily in fundraising but she's had a harder time convincing the political establishment of her worthiness.

"It's going to be very competitive," said Gary Clark, a political science professor at Dillard University. "There are those who may wish he may lose, but it will take more than wishing. He's a veteran politician and there are those who benefit by his being in office."

Jefferson's legal troubles surfaced shortly before Hurricane Katrina hit Aug. 29, 2005. Though he has not been charged with a crime, the allegations led to his loss of a spot on the House Ways and Means Committee.

Two of Jefferson's associates pleaded guilty to bribery-related charges; one, a Kentucky businessman, admitted paying more than $400,000 in bribes to a phony company headed by Jefferson's wife and family to obtain favors from the congressman.

Jefferson has denied any wrongdoing, and said he would explain his side in due course. So far he has not done that.

Jefferson, 59, has tried to soften voters' opinions of his legal troubles, invoking stories about how he has turned to God in these "difficult times." He has also cast Carter in attack ads as a socially liberal Democrat who supports same-sex marriages and late-term abortions.

Carter's spokeswoman, Cheron Brylski, said he had distorted her record and his own record of support for same-sex marriages and some forms of abortion.

For her part, Carter has hammered away at Jefferson, calling him a "hypocrite" and "unscrupulous" in a series of ads depicting children at a spelling bee who correctly spell the words used to denigrate Jefferson.

The bitter tone will likely be on full display Thursday night when the two candidates take part in their first head-to-head televised debate.