The ballot handed to Amanda Houston on Tuesday looked wrong.

It was too short and Gwen Graham wasn't on it, the candidate she had settled on for governor.

Turns out, her ballot was a crash course in Florida's closed primary system for the recent Alabama transplant. Republican-leaning, Houston registered "no party affiliation" when she moved to Plant City, not knowing it would shut her out of Tuesday's election.

"I'm not an independent who is going to vote for a Ralph Nader; I'm going to vote for Democrat or Republican," Houston, 28, said. "But I didn't have my mind made up when I registered to vote who could best represent our state."

Florida just concluded one of the most expensive and divisive primaries in its history. Yet still to be heard from are Florida's 3.5 million no party affiliation voters, a growing, unpredictable bloc that will now determine the direction this bellwether state takes in November.

The share of no party affiliation voters in a state of 21 million is larger now than at any point in the last two decades — 27 percent of all registered voters. For Republican Ron DeSantis or Democrat Andrew Gillum to win the governor's race, it will require winning over Floridians who couldn't vote for them Tuesday.

The problem: Tracking their behavior is difficult.

Some NPAs, as they're called, are true moderates, like Houston. Many others have strong political leanings but reject party labels.

Tampa resident Cheryl DeLong, 56, was a lifelong Democrat before changing to NPA out of frustration. Still, the issue that resonates most to her is equality — "from the richest among us to the poorest," she said — an ideal that closely aligns with Gillum's messaging.

Other NPAs don't give their affiliation much thought. The Florida Department of Highway Safety and Motor Vehicles asks anyone getting a driver's license if they want to register to vote. It's as simple as checking a box.

But for the next nine weeks, strategists and pollsters will try to break this group down and gauge how they will vote.

So who are these no-party affiliation voters?

• They are more likely to be white than Democrats but more likely to be a minority than Republicans.

• They are more often Hispanic than the average voter. The three counties with the highest share of NPAs are three of the four with the highest Hispanic populations — Osceola, Miami-Dade and Orange.

• Like Republicans, half are men, half are women.

• They make up a larger share of voters in the state's most populous counties. The glaring exception is Duval County. Jacksonville is home to a large black population, who overwhelmingly register as Democrats.

•NPAs don't vote as often as Democrats and Republicans.

In the 2016 presidential election, turnout among Democrats was 74 percent.

For Republicans, 81 percent. No-party affiliation? 63 percent.

Turnout during a midterm election is typically lower than in a general election, where turnout for NPAs dips to 50 percent.

NPAs vote as a bloc when there is national dissatisfaction with one party, said Tom Eldon, a Democratic pollster. It happened in 2006 amid anger over the war in Iraq and in 2010 in response to President Barack Obama's Affordable Care Act.

And there are signs it is happening this year, leading some to predict a so-called "blue wave" that favors Democrats. One recent example: Democrat Margaret Good in February won a special House race in a Sarasota district with 12,000 more Republicans. NPAs broke heavily in her favor, analysts said.

"The NPAs who have been turning out to vote tend to be more Democratic leaning and making a statement with whatever opportunity they happen to have," Eldon said.

The governor's race will test conventional wisdom that elections are won by maneuvering toward the middle. The nominees have staked positions on opposite ends of the spectrum, leaving a vast expanse between them.

RELATED COVERAGE: How the black vote carried Andrew Gillum to victory

Dem poll: With big advantage among independents, Andrew Gillum leads Ron DeSantis

In Gillum vs. DeSantis, anything can happen

On the right, DeSantis is an unflappable conservative congressman, illegal immigration hardliner and an outspoken defender of President Donald Trump. On the left, Gillum, the mayor of Tallahassee, is the state's first black nominee from a major party and a champion of progressive ideas like legalizing marijuana and Medicare for all.

Both campaigns are confident they can appeal to the non-affiliated middle.

"Education, environment, jobs, illegal immigration, those things I mentioned every single stop," DeSantis said on primary night. "We had a very good agenda, it resonated so we're going to keep focusing on those issues."

Gillum campaign strategist Kevin Cate said most voters can relate to the Democratic nominee's humble background as the son of a bus driver and a construction worker.

"All voters and in particular NPA voters are looking for something that's real," Cate said. "We haven't seen a candidate as real as Andrew Gillum in decades at the top of the ticket."

Fiscally conservative, but socially liberal, Gabriel Osejo, 25, was hoping one of the two parties would nominate someone from the middle. He's disappointed they didn't.

How can DeSantis and Gillum win his vote? "Make a push toward common ground, working with both parties," he said. "I'm all for moving more toward the middle."

If not, Osejo will write-in someone else — like he did in 2016.
Traditionally, political campaigns and academics assumed 40 percent of the population was reliably Democratic, 40 percent consistently Republican, and 20 percent up for grabs.

"There's so much polarization in the environment, it's probably down to 10 percent today," said Broward County-based Democratic consultant Ashley Walker.

It's apparent in the U.S. Senate race between Bill Nelson and Rick Scott. Polls consistently show them more or less tied, each hovering around 45 percent support.

Data is key in winning those elusive swing voters.

Using sophisticated polling information, computer modelling and consumer data, campaigns identify independent voters or even voters registered to the other party they see as potential supporters. Prius owner? Probably Democratic leaning. Garden & Gun magazine subscriber? Likely Republican.

"It's really about motivation now. It's two factors — do they swing and do they show up?" said Alex Patton, a Republican campaign consultant in Gainesville. "I guess we're about to spend millions and millions of dollars to find out."

Times/Herald staff writer Emily L. Mahoney and Times senior news researcher Caryn Baird contributed to this report.