RIO DE JANEIRO — There but for the grace of grassroots opposition and pliable political will goes Boston 2024.

It was supposed to be Mayor Martin Walsh and Celtics co-owner and Boston 2024 chairman Steve Pagliuca waxing poetic about their city’s burning desire to host the 2024 Summer Olympics, instead of Los Angeles Mayor Eric Garcetti and LA chairman Casey Wasserman.

The LA 2024 folks held their press conference here Tuesday, gushing about their bid to bring the Summer Games back to the United States for the first time since 1996. That task was supposed to be Boston’s, remember? No one at the US Olympic Committee or here in Rio with LA 2024 wanted to.

The Boston Olympic bid is now like the old Megaplex proposal or the new Fenway Park. It never existed. Boston has been cropped out of the USOC’s 2024 picture. It was all We Love LA and luminescent Magic Johnson-like smiles. The USOC folks want the ill-fated selection of Boston and the opposition and hostility that doomed its bid to disappear, the same way Rio officials want the folks from the Favelas to vanish during these Games.

Going by the revisionist history in Rio, Los Angeles — host of the wildly successful 1984 Summer Olympics — was the first choice all along. It’s not a break-glass-in-case-of-emergency bidder after Boston balked at hosting the Games, its bid imploding seven months after being selected over LA, San Francisco, and Washington in January 2015.

After being at my first Olympics for a week, Boston made the right choice in abandoning its bid.

The Olympics are tremendous. It’s an honor to cover, but they’re best enjoyed in someone else’s backyard.

In order to stage them, you have to completely subjugate your city to the Lords of the Rings. It’s like Airbnb for an entire city. But you’re staying in your home with millions of guests.

Streets of certain neighborhoods no longer belong to the residents. Roads get clogged. Transportation infrastructure gets strained. It’s an epic inconvenience and disruption for residents. A city like Boston, where tribalism reigns and a “what’s in it for me?’’ attitude pervades, might be built structurally for the Olympics, but not culturally.

This is what the USOC missed, and it might cost the US the 2024 Games. No matter how you slice it, the USOC is serving up the first runner-up in 2024.

The obvious question is: Why, if LA’s bid is so gilded, did it lose to Boston in the first place? That’s one that the folks at the International Olympic Committee might ask when LA is vetted alongside international heavyweights Paris and Rome and majestic Budapest.

“I don’t think it affects the bid at all,’’ USOC chairman Larry Probst told the Globe. “I have not heard a word about Boston in a year from any IOC member. I think that’s a thing of the past, and now we’re focused on moving forward.’’

Probst was courteous in answering a number of questions about Boston. He praised the city’s initial bid and was diplomatic. But it felt like I was asking him about his ex-girlfriend while he was out to dinner with his wife.

It’s hard to blame him, considering the ignominy that was Boston’s Olympic dalliance. The bid came crashing down like Mary Decker Slaney at the 1984 Games.

Technically, the decision to abandon the bid was mutual.

In reality, the city was DQ’d by an overwhelming lack of support for hosting global gym class, exemplified and amplified by the grassroots No Boston Olympics organization. This is the same group that initial Boston 2024 chairman and Suffolk Construction CEO John Fish dismissed in a teleconference the day Boston got the USOC nod.

“The No Boston Olympics group is a very small group of people in our city, who as a result of social media their voice is heard a lot louder than it would be in the past,’’ he said.

The final nail in the coffin was when Walsh balked at signing the host city guarantee, which would have put the Hub on the hook for any Olympic cost overruns.

Boston 2024 changed chairmen and messaging. They went from Fish to Pagliuca. The hard sell to the citizens of the Hub went from the honor and prestige of hosting the Games to reinventing two sections of the city: Widett Circle (heart of the much-maligned “Midtown’’) and Columbia Point.

It didn’t matter. Instead of lighting the torch, Bostonians burned their Olympic village to the ground.

By contrast, support for the Games in LA seems to be overwhelming. Garcetti said an independent poll had 88 percent of Angelenos in favor of hosting the Games again. He joked that sunshine got only an 84 percent approval rating.

The LA folks have some heavy hitters with their bid, including Olympic legends Janet Evans, the bid’s vice chair; Angela Ruggiero, the bid’s chief strategy officer; and the one and only Nadia Comaneci. They also have confidence and experience.

Garcetti said LA would need to construct only one venue to host the 2024 Games, which is music to the IOC’s ears after the race to completion in Rio. He called the LA bid a “virtually risk-free Games.’’

There’s no such thing, but Garcetti is the type of smooth-talking salesman Walsh is not.

Hockey Hall of Famer Ruggiero hails from Simi Valley, Calif., starred at Harvard, and works in Boston. She said LA’s previous experience with the Games accounts for the difference in support.

“Any city that hosts the Games says immediately, ‘We want to do this again,’ ’’ said Ruggiero, who is on the USOC board of directors. “You see Olympic-ism. You feel it. The citizens are impacted in a way that’s different than watching on TV.

“And as much as you can talk about it, and I as an Olympian can say, ‘Wow, this will be fantastic.’ If you don’t have that from your citizens, it’s a trickier situation.’’

Boston’s is the bid that never was.

Like an Olympic athlete who wins a medal and tests positive for performance-enhancing drugs, it has been stricken from the record.

Christopher L. Gasper can be reached at cgasper@globe.com. Follow him on Twitter @cgasper.