In the cauldron of instability that is Miami City Hall, one of the biggest pot-stirrers of all was former mayor and commissioner Joe Carollo.

In 10 years on the commission and a single full term as mayor, Carollo fulminated against communist sympathizers and foes real and imagined, spun elaborate conspiracy theories, turned vindictively on friends and supporters he thought had crossed him, and once even wound up grappling with another commissioner behind the dais during a meeting.

Critics considered him all but unhinged at times, but there were always those who insisted that Joe was just crafty, that there was substance to the man and sound instincts behind the antics. And, in fact, Carollo was not infrequently proven right: When he alleged that massive vote fraud swung the 1997 mayoral election against him; when, upon gaining the mayor’s seat on court order, he claimed his predecessors had left the city in a giant financial hole; and when he accused his own city manager of looting a charity.

Yet after every unlikely vindication, every time Carollo seemed to regain public favor, Crazy Joe would emerge to shoot Crafty Joe in the foot.

After earning widespread credit as mayor for helping stave off bankruptcy, stabilizing management and building up a substantial budget surplus, in 2000 he embroiled himself in the ethnically divisive case of boy rafter Elián González. Protesters began pelting City Hall with bananas on a daily basis after Carollo, who at every opportunity attacked federal efforts to return the boy to his father in Cuba, abruptly fired his police chief, William O’Brien, for failing to warn him of the Border Patrol raid on the home of the boy’s Miami relatives.

Carollo’s political career finally imploded along with his second marriage at the end of his mayoral term, when he allegedly flung a cardboard tea container at his wife’s head and spent the night in jail. On leaving office after losing his 2001 reelection bid, Carollo was, to all appearances, isolated and done politically.

Later, though, just before he dropped out of the public eye for several years, Carollo got even with the judge who awarded a big chunk of his city pension to his ex-wife, by conspicuously helping a challenger unseat the incumbent.

Now, as the 57-year-old Carollo embarks on what seems the unlikeliest of public third acts as Doral’s city manager — newly elected Mayor Luigi Boria shocked the local political establishment last week by plucking the former Miami mayor out of obscurity to run the fast-growing suburban city — observers, critics and his remaining allies are trading bets on which Joe will show up for work, and how long he will last.

Boria, who brushed off questions from a reporter on Thursday and Friday about how the mercurial former politician became an apparently trusted advisor, said he’s not worried.

“I have no reservations,’’ Boria said, noting Carollo’s experience in public office and overseeing a public budget. “It has nothing to do with trust. It has to do with one’s curriculum vitae … It has nothing to do with friendship. It has to do with one’s experience, one’s capabilities.”

Outwardly, at least, the Carollo who reemerged this past week looks grayer but otherwise little changed from the politician most voters last laid eyes on 11 years ago: stiff, formal, serious, speaking in a near-monotone no matter how inflammatory his words, and little given to smiling or small talk.