Incumbent Democrat Mary Landrieu (36 percent) is in the fight of her political life as she leads Republican challengers Bill Cassidy (35 percent) and Rob Maness (11 percent) in the Louisiana race for U.S. Senate, according to a Suffolk University/USA TODAY poll of likely voters. Five other candidates listed on the Louisiana ballot are each polling at 1 percent or less, while 14 percent were undecided and 1 percent refused a response.

Louisiana holds a “jungle primary” for statewide offices, whereby candidates of all parties vie to win one of the two top spots, regardless of whether the finalists are from the same or opposing political parties. If a candidate wins 50 percent or more, the election is over; however, if no candidate reaches 50 percent, then a “runoff” takes place within a month. If necessary, the Louisiana runoff election would take place on Dec. 6.

“Senator Mary Landrieu benefits from seven others splitting the anti-incumbency vote,” said David Paleologos, director of the Suffolk University Political Research Center in Boston. “But in a one-on-one scenario, she is vulnerable, not only because of her own disapproval ratings, but also because likely voters are venting frustration towards the president and his policies.”

Landrieu’s job disapproval was 54 percent, slightly better than President Obama’s 60 percent disapproval rating. Overall, 62 percent of voters said that Obamacare was generally bad for Louisiana. Among those still undecided in the November election, Landrieu has a 60 percent unfavorable rating.

The poll is part of a midterm elections partnership between Suffolk University and USA TODAY that includes polling and analysis of key U.S. Senate and other statewide races and key issues. The poll was conducted in association with the Daily Advertiser and WWL-TV, a CBS affiliate located in New Orleans.

In a potential runoff between Cassidy and Landrieu, the Republican opens up a 7-point lead, due to the high Landrieu negatives among primary voters who support Maness (89 percent).

Fifty-nine percent of voters said they did not trust the federal government to handle the Ebola crisis. Respondents said that health care and jobs are the issues that most concern them.

Methodology

The survey was conducted through random-digit dial of landline and cell phones. All respondents said that they are very likely to vote or had already voted in the Nov. 4 election. The field of 500 likely general-election voters was conducted Thursday, Oct. 23, through Sunday, Oct. 26. The margin of error is +/-4.4 percent at a 95 percent level of confidence. Results are posted on the Suffolk University Political Research Center website. For more information, contact David Paleologos at 781-290-9310.