Billionaire developer Jeff Greene is an unconventional Democrat running an unconventional campaign for Florida governor. So, naturally, his ideas on how to change Florida's vast public education bureaucracy stem from an unconventional place.

Standing in a former West Palm Beach car dealership that he converted two years ago into a school house, Greene explains how the future of Florida's schools lies in shrinking class sizes, replacing letter grades with detailed evaluations and adopting the latest technologies.

After all, he says, those are some of the reasons The Greene School is a model for the rest of the state.

"It's not that difficult to make changes in education," Greene says matter-of-factly — even though he was so underwhelmed by the state of Palm Beach County schools two years ago that he went ahead and built his own.

Dissatisfied with the public and private school options for his three sons, Greene and wife Mei Sze opened their own school in 2016, plunging millions of their own dollars into the creation of a campus for gifted kids. At the time they said they hoped it would become a beacon for young professionals pondering a move to South Florida.

Now, Greene — the latest billionaire to adopt education as a passion — hopes it will be a beacon for voters weighing his candidacy.

With families preparing to return their children to school for the year and voters deciding on a candidate to represent their party in the general election, Greene has made education a central tenet of his platform and modeled it around the brick-and-mortar of The Greene School. He's called the school "an innovative model for what Florida public schools could be if Tallahassee made public education a priority."

In so doing, he's dubbed himself an "accidental educator."

But while education is an all-consuming issue for Democratic voters and candidates, Greene's decision to promote a private school that vets students with an IQ exam is an awkward one, considering that his own party has spent the last 20 years trying to reverse a tide of legislative bills that have eroded teacher tenure, pushed public money into for-profit management companies and steered several hundred thousand students away from traditional schools.

The concept is so uncomfortable to the Florida Education Association that president Joanne McCall said the union's board would have to meet to discuss whether they could support Greene in the general election should he emerge as the Democratic Party nominee on Aug. 28.

"We're troubled by the fact that he created a private school," said McCall, whose union has endorsed former congresswoman Gwen Graham. "That's problematic and something we'll need to discuss if he makes it through to the general election."

McCall, who said Greene was not interviewed by the union because he belatedly got into the race on the same day that candidates were vetted for endorsements, said she would rather have seen Greene partner with public schools than avoid them completely.

But inside the Greene School, Greene, 63, sees a new framework for education emerging from a blank slate. The building resembles a co-working space at Google more than it does a school house. There are classrooms made of floor-to-ceiling glass panels, indoor trees and plenty of gizmos and gadgets for every student at the school, which runs from Pre-K to seventh grade and will expand to include eighth graders next year.

The school will open for its third year on Sept. 4 with about 110 students. About 80 percent of the student body is white, 10 percent is Asian and the remainder is black or Hispanic.

The students who will roam its halls hail from public and private schools from as far north as Palm City and as far south as the Boca and Boynton area. All students passed an IQ test and were favorably recommended by staff to gain admission.

About half of the student body is on "need-blind" scholarship assistance; the rest pay between $21,000 to $29,000 a year, which covers organic lunch, a snack, after-school activities and after care. Greene says he doesn't accept tax-credit scholarships designated for low-income children and opposes such vouchers, though he supports the Gardiner and McKay scholarships for students with special needs.

"You can't rob the public schools," he says, adding that public money should fund public education. Teachers at his school start around $50,000 in salary, have two hours of planning daily and have maternity and paternity leave.

As two of his sons scamper, Greene watches a $1,500 3-D printer work its magic. Every school will have one when he's governor, he says.

His boys turn their attention to a pair of virtual-reality goggles, part of a high-tech network that goes as far as to include video conferencing software for students and teachers in order to eliminate sick days. Greene believes that technology is dramatically changing the employment landscape for young and particularly blue-collar workers, requiring public schools to make significant investments in the latest gadgets and software.

He says he built the school into an incubator of what public schools could look like if voters put him in the government mansion: flexible learning, empowered teachers and a love for the arts.

"Everything we're doing here can be used in public schools," said Greene, who says that he felt powerless as a parent to change Palm Beach County's public school system.

As governor, though, Greene says things would be different.

Some aspects of the Greene School can't be duplicated, he acknowledges, like a ratio of two teachers for every 16 students. But perhaps physical education time could include lessons on mindfulness. And classes like art, music and yoga aren't electives — they're built into the core curriculum.

Another change that he argues can be adopted in public schools: Instead of grades, elementary students get a "narrative assessment" — a six- to eight-page report that details skills accomplished and what needs to be improved.

"One of the biggest complaints parents have is the report card system," said third-grade teacher Samantha Smith, who previously taught at Binks Forrest Elementary in Wellington.

In her three years teaching kindergarten in public school, "there were a lot of requirements that did not enhance the student's experience," she added.

Teachers at the Greene school are free to spend extra time to help students.

They can also cater to students' needs more and understand their learning habits through a program called AltSchool, which is backed by Mark Zuckerberg.

"We could be this leader in using technology as a tool to help teachers make this the number one education system in the country," Greene said. "Just like we did here, I'm happy to leave Florida" to find what works best.

On the campaign trail, Greene spouts wonky-sounding statistics about how only 56 percent of third-graders are reading at grade level — and how that can be a predictive measurement of whether they'll end up in college or prison. He says the state's school system is ranked in the bottom 10 in the country.

But how much does Greene really know about public schools? In an interview with the Tampa Bay Times Editorial Board last month, Greene responded to a question about McKay Scholarships with a question of his own: "What's that?"

"Building your own school doesn't mean you understand education, just like building a restaurant doesn't make you a top-tier chef," said Dwight Bullard, a former Democratic state senator and Miami-Dade public schools teacher. Bullard is now the political director for New Florida Majority, which has endorsed Andrew Gillum in the Democratic primary.

But even if Greene fancies himself an educator, he doesn't hold himself out as an expert. Greene would make a great governor, "because he will admit when he doesn't know something" and find the best team that knows how, said Denise Spirou, head of The Greene School.

"Education is something I've just become comfortable with," Greene said.

As governor, Greene says he'd scrap the Voluntary Pre-Kindergarten program and push for two years of universal Pre-K. He wants to roll back vouchers and charter schools, enforce class-size limits and pay teachers more, especially those who teach computer science, to be competitive with the private sector.

Greene also believes that community college should be free for anyone who can't afford the tuition. That's the model he uses for the Greene School, in which he estimates he's poured in more than $20 million since 2016.

But largely, Greene says he'd reprioritize the state's spending on education by raising taxes "on the super rich" and "vetoing any tax dollar going to charter or private schools." And he says, as governor, he'll rely on the best experts to help him do it.

"We'll get the best advisers," he says, "from the best school systems in the world."