Voters swept Miami-Dade Mayor Carlos Alvarez out of office by a stunning margin Tuesday, capping a dramatic collapse for a politician who was given increased authority by voters four years ago to clean up much-maligned county government but was ushered out in the largest recall of a local politician in U.S. history.

The spectacular fall from power comes after two years of missteps, ranging from granting top staffers big pay hikes to construction of a publicly funded stadium for the Florida Marlins to implementation of a property-tax rate increase that outraged an electorate struggling through an ugly recession.

Alvarez tried to fend off ouster by twice filing suit to block a recall vote. After the lawsuits went nowhere, he defended his record in speeches, radio and television appearances and paid advertisements, arguing that he made the tough calls to preserve vital services for residents.

But voters responded by handing the mayor a humiliating defeat: Nearly nine of every 10 voted to remove Alvarez from office.

“The voters have spoken and a time of healing and reconciliation must now begin,’’ Alvarez said in a statement Tuesday night. “No matter which side of the recall issue, one thing is certain: We all care very deeply about this community… I wish the next mayor of Miami-Dade County much success.”

Tuesday’s vote served notice that the public is thirsting for widespread reform at County Hall, long dominated by entrenched politicians and insiders. County Commissioner Natacha Seijas was similarly recalled Tuesday in a resounding defeat. For 18 years she represented a district that includes Miami Lakes and Hialeah and was widely regarded as the most powerful politician on the commission.

The two ousters come on the heels of Dorrin Rolle’s defeat in November, which marked the first time a sitting county commissioner has been defeated in 16 years.

More than 200,000 people cast votes in the election. Noel Sanz, of Kendall, echoed what many other voters told reporters Tuesday: He wants new blood at County Hall.

“I think it’s time to get some of these guys out of power and get someone else to do the job,” Sanz said.

The campaign to recall Alvarez was launched in October by billionaire businessman Norman Braman after Alvarez successfully pushed for a property tax-rate increase to help plug a gaping budget hole. At the same time, Alvarez pushed for labor contracts with employee unions that included pay hikes for most county workers this year.

“County voters have demonstrated by their ballot that they are tired of unaccountable officials, of being ignored, and of being over-taxed in this very difficult recessionary time,’’ Braman said Tuesday night. “We’ve empowered the people of this county to take back the government and ask the government to be responsive to the people.”

He urged the county commission to set an election for a new mayor rather than take it upon themselves to appoint someone until the next countywide election early next year.

Braman argued that the recall effort is a first step in reforming county government. Among other things, he has called for term limits and making it easier for voters to amend the county’s governing charter. But precisely what reforms, if any, will be adopted remains an open question. Many sitting county commissioners have shown little willingness to change.