Advocate photo by Matthew Hinton -- New Orleans Mayor Mitch Landrieu speaks about preparations for Tropical Storm Nate. 

Political endorsements have been a big part of the New Orleans mayoral race story, largely because one candidate, former Municipal Court Judge Desiree Charbonnet, has cornered the market.

Charbonnet is running a television testimonial from U.S. Rep. Cedric Richmond, and one of her recent mailers proclaims in bold letters that "Cannizzaro endorses Charbonnet." That would be District Attorney Leon Cannizzaro, of course.

Charbonnet was also in contention for the most prominent endorsement of all. Outgoing Mayor Mitch Landrieu had indicated until recently that he may choose a candidate to back in Saturday's primary, and had reportedly narrowed the choice down to Charbonnet and City Councilwoman LaToya Cantrell. But Landrieu said Tuesday that he'd sit this one out, although he may still endorse a runoff candidate.

His decision at this late date may be newsy, but it's unlikely to have much effect on the outcome. Landrieu is thought to have preferred several state lawmakers who declined to run, but doesn't have close ties to the politicians who qualified. And his endorsement, even more than Richmond's and Cannizzaro's, would have been double-edged.

Landrieu remains more popular with voters than Cannizzaro and nearly as well-liked as Richmond, according to a recent poll taken for The New Orleans Advocate and WWL-TV. The survey of 500 registered voters found that 57 percent approve of the mayor's job performance, compared to 46 percent for Cannizzaro and 59 percent for Richmond.

Yet the next mayor doesn't only have reason to distance him or herself from Landrieu's shortcomings and controversies — things like the dysfunction at the Sewerage & Water Board and his campaign to take down Jim Crow-era monuments — but also needs to prove his or her independence. That's true for anyone running to replace a two-term incumbent, but particularly so when that incumbent is as hands-on and strong-willed as this one. 

Yes, Landrieu's support for a given candidate might reassure some voters, but it's just as likely to drive some away. Either way, the reality that he won't play a major role in the choice of his replacement underscores how rapidly we're approaching the end of an era.

Follow Stephanie Grace on Twitter, @stephgracela.