Florida Democratic voters delivered another shock upset to their party's establishment, nominating state Rep. Angie Nixon, a democratic socialist from Jacksonville, over Alex Vindman, a moderate former national security professional who played a central role in President Donald Trump's first impeachment.

Democrats have hoped to mount a comeback in the diverse, populous and economically dynamic state, but they have struggled to craft a message that resonates with Florida's electorate. Nixon's upset sets up a long-shot challenge to U.S. Sen. Ashley Moody, a former state attorney general whom Gov. Ron DeSantis selected to fill the seat after it was vacated by Marco Rubio, whom Trump chose as secretary of state. Moody and Nixon will meet in a Nov. 3 special election to serve the remainder of Rubio's term, which runs through January 2029, after which the seat is up again for a full six-year term.

The race has already inflamed tensions within the Democratic Party over how to energize liberal voters eager for unapologetic, combative candidates without alienating the independents and moderates who have been key to winning in battlegrounds.

"If you're surprised by tonight's election results, you haven't been paying enough attention to what's happening in the South," said Britney Whaley, southeast regional director of the Working Families Party, which backs populist candidates. "Tonight's election results must be a wake-up call to a political establishment that believes a populist message can't win in the South. Angie's campaign proves voters will respond to a bold economic vision that meets their basic needs."

A spirited progressive who had the backing of Reps. Rashida Tlaib of Michigan and Ilhan Omar of Minnesota, Nixon recently joined the Democratic Socialists of America. Her win carries the democratic socialist movement's national momentum — most visibly New York City Mayor Zohran Mamdani's 2025 victory — into a statewide race in the South. She championed policies such as universal healthcare and childcare and has been an outspoken critic of U.S. foreign policy and the war in Gaza.

In May, Nixon protested the Republican-controlled Florida legislature's redistricting of the state's congressional maps by shouting through a megaphone during a hearing. She was later reprimanded by an ethics committee but earned plaudits from Democratic allies and voting rights advocates for her demonstration.

The fundraising gap between the two candidates was stark. Vindman raised about $16 million in the race and had spent more than $9 million by the end of July. Nixon, by contrast, had raised just shy of $1 million. Progressives immediately touted her win — achieved despite being outraised by roughly 16 to 1 — as a sign of greater momentum for the region.

Vindman served on the White House's National Security Council during Trump's first term. His testimony was central to Trump's first impeachment, which centered on a phone call in which the president pressured Ukrainian President Volodymyr Zelenskyy to investigate Joe Biden and his family. Vindman became a national Democratic star and a target of Trump's ire for his actions, a dynamic that garnered him millions in small-dollar donations.

His twin brother Eugene, who also served on the National Security Council, is serving as a Democratic congressman from Virginia.

"Rep. Nixon ran a strong campaign. I will be standing by her side in the fight against Ashley Moody. I hope you'll join me," Vindman said in a statement after conceding the race.

Democratic leaders such as Senate Minority Leader Chuck Schumer had hoped Vindman's reputation and campaign war chest would help turn what election analysts considered a solidly Republican seat into a more competitive race. But Nixon's upset victory has now buoyed already high Republican confidence in the state. An immediate question for party leaders is whether national Democratic groups pour money into Florida — one of the country's most expensive states to campaign in, spanning roughly a dozen media markets — or redirect it toward races they view as more winnable.

Once an archetypal political battleground, Florida has shifted to the right since 2016. Republicans overtook Democrats in statewide voter registration in 2021 for the first time, and their lead has since stretched to several hundred thousand voters. Gov. Ron DeSantis won reelection by about 19 percentage points in 2022, and Trump carried the state by about 13 points in 2024. Trump himself moved his residence to his Mar-a-Lago resort after leaving the White House in 2021 following his first term.

This story was originally featured on Fortune.com.