“When it comes to the judges, it’s a beauty contest,” said David Custin, a consultant and Hialeah native who has worked for Republican and Democratic candidates.

“When it comes to a district or a race where it’s a jump ball, that’s where the boleteros come into play,” Custin said. “You could have local bartering. The boletero says: ‘Be with me, I’ll put in a good word with the mayor or the councilman.’ ”

Like Ulvert and other consultants who spoke with The Miami Herald, Custin said he doesn’t use boleteros.

“Boleteros are part of a patronage system or a shortcut or they get hired by campaigns who don’t know how to do it,” Custin said. “You don’t have to have them. People do it because they’re there.”

Florida House Republican leader Carlos Lopez Cantera, who’s running for county property appraiser, said Cabrera offered her services but he declined. He said he feels uncomfortable with ballot brokers.

“People would not solicit these services if people stopped paying for them,” he said.

Former Rep. J.C. Planas, who worked for John McCain’s presidential campaign in 2008, said boleteros are a dying breed — and not worth the money.

“Most of these people are snake-oil salesmen selling a campaign a bill of goods,” he said. “It’s a fraud.”

Boleteros seldom show up on campaign-finance reports, and instead operate like off-the-books subcontractors who are paid by campaign consultants in cash to get out the vote.

In some cases, a subcontractor for a campaign consultant can hire a boletero, who is therefore kept three transactions away from the campaign.

No one has admitted to employing Cabrera.

A private eye, hired by an unknown client, followed her into a building that houses the Hialeah campaign office of Miami-Dade Mayor Carlos Gimenez, who has denied hiring Cabrera. She has been charged for possessing 31 voted absentee ballots over two days.

A top Gimenez consultant, lobbyist Al Lorenzo, signed an affidavit saying he didn’t hire her. Lorenzo also works for State Attorney Katherine Fernández Rundle, who’s facing a tough reelection, and has recused herself from the investigation of Cabrera.

Boleteros don’t work alone. They’re usually used in coordination with sophisticated absentee ballot-turnout operations.

First, campaigns target likely voters identified through database searches of the state’s voter file. They’ll call the voters and ask for their support and whether they’d like to vote early by absentee ballot.

The campaign will then send an absentee-ballot request form. Once a voter’s request is processed in the state system, it can be like blood in the water that alerts the shark-like senses of aggressive campaigns. They start calling and mailing voters.

Campaigns time when absentee ballots arrive at someone’s house.

At that point, they dispatch boleteros to make face-to-face contact with known voters to persuade them to fill out the ballot.

Cira and Jose J. Machado, Hialeah residents for 23 years, are typical of the voters that boleteros target. Both are elderly and have health problems.

Jose Machado, suffering from Parkinson’s and a bruised hand, met Cabrera at a Sedano’s grocery store.

“She said she would take the ballots to the mail. I gave her my address,” he said.

The couple said they filled out and voted their own ballots without Cabrera’s help.

Boleteros aren’t supposed to collect ballots, but sometimes voters request that they mail it for them or keep it in their possession.

Before absentee-ballot fraud marred Miami’s 1997 mayoral race, boleteros would collect boxes’ worth of absentee ballots that they’d drop off at the elections office. That ended with legislative reforms in 1998 that, among other things, limited third parties from possessing absentee ballots.

These days, “boletera” is a slur to consultants like Sasha Tirador, who was labeled “the absentee-ballot queen” by former Hialeah mayor and ex-congressional candidate Raul Martinez.

“He knows a phrase like that would hurt a consultant,” she said, “If you are labeled as a ‘boletera,’ it would hurt your business.”

Miami Herald staff writers Daniel Chang and Christina Veiga contributed to this report.