NEW ORLEANS — New Orleans voters choose among 18 candidates Saturday for mayor, seeking a successor to Mitch Landrieu for such daunting challenges as a stubborn violent crime rate and dysfunction in the agency that maintains the aging pumps that clear storm runoff from the low-lying city.

Nobody is expected to secure a majority needed to win outright Saturday, meaning the top two finishers would head to a November runoff.

Polls and analysts say there are three strong contenders for those two spots: Michael Bagneris, a former state civil court judge; Latoya Cantrell, a City Council member; and Desiree Charbonnet, a former municipal court judge.

All three are Democrats vying to succeed Landrieu. A term-limited Democrat, Landrieu won office in 2010 and 2014 with landslide victories and is credited with spurring a strong recovery from the 2005 levee failures that followed Hurricane Katrina.

Still, after heading downward in Landrieu’s first term, the city’s murder rate has climbed in the past two years. Efforts to replenish a police force that dwindled during budget cuts soon after Landrieu took office have been slow. Meanwhile, flash floods in August led to revelations about non-functioning pumps, broken power turbines and managerial dysfunction at the agency responsible for running them.

None of the three leading candidates is a political novice although Bagneris and Charbonnet have the deepest political roots. Bagneris is an attorney who served as counsel to former Mayor Dutch Morial before serving as a civil court judge for 20 years. He ran unsuccessfully against Landrieu four years ago. Charbonnet is from a politically active New Orleans family. She held office as the city’s recorder of mortgages before moving on to municipal court. Both are New Orleans natives.

Cantrell came to New Orleans from California to study at Xavier University. She gained notoriety as a neighborhood activist following Hurricane Katrina in 2005 and was elected to the council in 2012.

The race is notable for demographic reasons. It could result in a woman being elected mayor of New Orleans for the first time. And all three leading candidates are black. Landrieu, who won with strong biracial coalitions in his two victories, was the mostly black city’s first white mayor since his father, Moon Landrieu, served as mayor in the 1970s.

A racially fraught issue that rocketed Landrieu to national prominence this year — his leadership in removing four Jim Crow era monuments to Confederate figures from public view — came up at a televised debate on Wednesday.

Bagneris said there would be no more removal of such monuments, or renaming of streets or schools bearing Confederate era names, without a vote of New Orleans residents. “That is one of things that cause a wedge in our community,” he said. He refused to say how he would vote on such issues.

Cantrell, who as a council member voted for removal of the four monuments, said the council is the appropriate place to consider such issues. Charbonnet expressed similar views, and also said of the issue: “We need a pause on some of this right now. It has caused so much division in this community.”