On Tuesday, Floridians picked Tallahassee's progressive black mayor, Andrew Gillum, and right-wing hardliner, Rep. Ron DeSantis, to face off in the governor's race this fall.

Both candidates defeated establishment favorites — Gillum with the support of Sen. Bernie Sanders, and DeSantis with President Donald Trump's endorsement.

Many see what will undoubtedly be a polarizing general election as a proxy war between Sanders and Trump.

On Tuesday, Floridians picked their first-ever black nominee for governor, Tallahassee mayor Andrew Gillum, and a right-wing hardliner, Rep. Ron DeSantis, to battle it out for leadership of the country's largest swing state.

Both candidates defeated establishment favorites — Gillum with the support of the left-wing of the Democratic Party, including Sen. Bernie Sanders, and DeSantis with President Donald Trump's strong endorsement.

Gillum's win was a surprise — his strongest pre-election poll had him at 16% of the Democratic vote (he ended up with 33%) and he was far outspent by his multi-millionaire opponents, the strongest of whom spent $12.5 million to Gillum's $2.5 million.

And while DeSantis's victory over state agriculture commissioner Adam Putnam was expected, he managed to secure a 20-point lead while also being outspent — two-to-one — by his opponent.

GOP strategist Matt Mackowiak called both wins "shocking."

"Nobody would have predicted a DeSantis versus Gillum general election six months ago," he said.

The candidates — both married 39-year-old dads of young children — are running on radically different agendas in the country's third-most populous state.

DeSantis, a member of the ultra-conservative House Freedom Caucus who saturated his campaign with mention of Trump's support, campaigned on his military background and deeply conservative stances on abortion, gun rights, and illegal immigration. Gillum, the son of a bus driver and construction worker, highlighted his working-class roots, with promises to invest heavily in the state's public schools and fight for stricter gun regulations and Medicare-for-all.

While gubernatorial candidates are often characterized by their centrism, Florida is yet more proof of the ascendance of the progressive left and Trumpian right this year.

Rep. Ron DeSantis with President Donald Trump at a Florida rally in July. Joe Raedle/Getty Images

A Sanders-Trump proxy war?

Some are calling the general election race a proxy war between Sanders, who endorsed and campaigned with Gillum, and Trump.

While Gillum ran to the left of Democratic Rep. Gwen Graham, the primary front-runner and daughter of a former Florida governor and US senator, he was also a 2016 delegate for Hillary Clinton and appeared on an early list of Clinton's potential vice presidential picks.

Still, the mayor ran on a deeply progressive platform, which included the elimination of Immigration and Customs Enforcement — a call that's gaining traction on the left — and Medicare-for-all. His win — along with other insurgent upsets — is a remarkable testament to the rejection of Clinton-style centrism in the Democratic Party. Also on Tuesday, Arizona Democrat David Garcia, a progressive who supports Medicare-for-all, clinched the party's gubernatorial nomination in that state.

In Florida, centrist Democrats lost the last two gubernatorial races by less than a single point to Republican Gov. Rick Scott.

"If Florida voters want an antidote to Trumpism, Andrew Gillium fits it. He's not part of the Trump-DC-swamp but, instead, a mayor who got stuff done," said Jesse Ferguson, a Democratic strategist and top spokesman for Hillary Clinton's 2016 campaign.

Rep. Ron DeSantis with his daughter in a campaign ad. Screenshot/Ron DeSantis for Governor

Republicans are already characterizing Gillum as far left of Florida's mainstream. Trump called the mayor a "failed Socialist ... who has allowed crime & many other problems to flourish in his city" in a Wednesday morning tweet, and the Republican Governors Association on Tuesday called Gillum a "radical far-left politician."

Gillum, for his part, has attempted to frame his progressive solutions to polarizing issues like healthcare and criminal justice reform as pragmatic, a-political, "commonsensical" solutions that will appeal to Floridians across the ideological spectrum.

Meanwhile, DeSantis recently released an ad poking fun at his own attempts to tie himself to Trump. In it, DeSantis's wife explains that while "people say Ron's all Trump ... he is so much more," while the congressman "builds a wall" with his toddler daughter and reads Trump's "The Art of the Deal" aloud to his son.

A 2020 test

Given DeSantis's close ties to the president, the race in Florida this fall will undoubtedly become a referendum on Trump's presidency and a test of the progressive movement's strength in the lead-up to the 2020 presidential election.

But Mackowiak noted that midterm turnout is traditionally quite different — older, more conservative-leaning, and less racially diverse — than presidential election turnout. He argued that Gillum will need to pivot more to the center than DeSantis will.

"Florida's a Republican state, period," he said. "Obama was able to flip it, he was a unique candidate ... but in a midterm election year I don't think there's a question that it's a Republican state."

Florida's Democratic primary will also likely mirror the battle between progressive and centrist candidates on the left in 2020. In what will likely be a 2020 primary, Democrats will face the challenge of uniting themselves behind a single candidate. The situation is similar in Florida, where four other Democrats spent tens of millions competing against Gillum.

While it's unclear how nationalized the race will become, it will certainly be one of the most important — and closely-watched — of the cycle.

"We're going to make clear to the rest of the world that the dark days that we've been under coming out of Washington, that the derision and the division that have been coming out of our White House, that right here in the state of Florida we are going to remind this nation of what is truly the American way," Gillum told his supporters on Tuesday night.