Here’s an idea: Let’s not bother with mayoral elections in Boston.

Unless the guy on City Hall’s fifth floor decides he doesn’t want the job anymore — which is the only way somebody new ever gets a crack at it — mayoral contests are just a waste of time and money. I’m as fond of the democratic process as the next person, but really, unless we stop going through the motions here, what’s the point?

You know the last time an incumbent mayor was defeated in Boston? 1949. That was after Mayor James Michael Curley had spent five months in prison for corruption. And even then it was close: John B. Hynes won by fewer than 12,000 votes, or 4 percent.

The only near-upset since then was in 1975, when it looked like Kevin White might go down to Joe Timilty. The city was on its knees financially at the time, says former city councilor and Boston politics oracle Larry DiCara. Boston was in the middle of the school desegregation order, race relations were awful, and residents were fleeing the city. Still, White won by 7,400 votes, or almost 5 percent.

For Boston voters, sitting mayors are habit-forming, like Dunkin’ Donuts or jaywalking. That’s partly because thousands owe their jobs to them: Add employees’ friends and family, and you’ve got an instant base, not to mention plenty of campaign volunteers.

Also, mayors get around, their daily festivals of glad-handing hard to distinguish from a full-fledged campaign. Half the city had met Mayor Tom Menino personally. His successor, Marty Walsh, the first-term incumbent, is headed in the same direction, his calendar jammed with neighborhood events where he stands in the spotlight while potential rivals grumble on the sidelines.

Boston mayors are powerful politically, too, and that’s especially true of Walsh, a former legislator and union official. People who would make spectacular mayors wouldn’t dream of running against him.

“The mayor is on top of this large pyramid of power, and I don’t think that’s going to change,’’ DiCara says.

We’ve seen this eleventy times before, and here we are again. The mayor’s only serious opponent is Tito Jackson, a sacrificial lamb . . . . um, brave city councilor, who needs lightning to strike to preserve him from the fate that befell all who went before him. Right now, Jackson has less than $80,000 in campaign funds. Walsh has amassed $4 million.

As if the city councilor’s climb wasn’t steep enough, he has just had an especially awful week. On Wednesday, the Globe reported on his work as a sales rep for a pharmaceutical company from 2004-2006. Jackson’s job was to persuade doctors and pharmacies to dispense an opioid called Kadian. The overprescription of opioids has been a major factor in the national addiction epidemic, and Jackson has criticized Walsh for failing to do enough to help those affected. That looks bad enough, but Jackson made it worse by pushing a WGBH reporter’s arm after she asked him about this on Tuesday night. He has since apologized.

The shame of it all is, Walsh — like every other incumbent — truly deserves a real challenge. He has done some terrific things, bringing innovation to city government and standing up for marginalized Bostonians, including undocumented immigrants. But he also has made mistakes. His handling of the aborted Olympics bid was awful. Worse still was the IndyCar debacle, where Walsh’s lack of caution led him and the city into a spot where they appear to have been swindled. The abrupt closing of the shelters and drug treatment facilities on Long Island and the furor over racism at Boston Latin would put deep dents in any incumbent at election time. On top of it all, federal prosecutors have indicted two of Walsh’s aides, in a probe that has left a cloud hanging over the mayor himself.

Perhaps that cloud will dispense enough lightning to make Jackson mayor. Nobody should hold their breath, though.

A real electoral contest is a chance for much needed debates about race, crime, education, and other vital subjects. Really testing Walsh would make him a better mayor, too. But instead of real, we’ve got this lopsided, expensive charade.

Who are we kidding? Let’s call the whole thing off.

Globe columnist Yvonne Abraham can be reached at yvonne.abraham@globe.com. Follow her on Twitter @GlobeAbraham.