With the party’s largest and most diverse presidential field ever, Democrats have had so many choices, from rebuild-the-system socialists, to pro-business incrementalists, and everything in between — even a new-age spiritual guru.

And yet, the contest has been remarkably static, not the wild brawl that might have been expected.

The same three candidates — Joe Biden, Elizabeth Warren and Bernie Sanders — have led nearly every poll, nationally and in the early voting states. Only two others, Kamala Harris and Pete Buttigieg, have regularly topped 5%.

Now, the Democratic primary enters a new phase designed to thin the herd. Tighter qualification benchmarks have produced a televised debate this week that will have just 10 candidates sharing a stage. With a smaller national debate, intensifying campaign schedules, and some contenders falling by the wayside, the question is whether others besides the front-runners can break through.

“For candidates that didn’t have a national following it’s been hard to gain one,” said Morgan Jackson, a Democratic strategist based in North Carolina. "So many people are competing for limited time.”

Besides Biden, Sanders, Warren, Harris, and Buttigieg, also qualifying for Thursday night’s debate in Houston are Cory Booker, Julián Castro, Amy Klobuchar, Beto O’Rourke, and Andrew Yang.

Already, many analysts are framing the debate around Biden, Sanders, and Warren, since the three front-runners will share a debate stage for the first time. But in interviews, more than a dozen party officials, operatives, and activists warned against drawing early conclusions. Instead, they said to expect volatility.

“Some campaigns are stronger than others right now, but to say the top three will be the top three on caucus night, I would bet money against that,” said Sean Bagniewski, chair of the Polk County, Iowa, Democratic Party.

After all, Iowa’s caucuses and New Hampshire’s primary are relatively intimate elections that can produce surprises, generating momentum that carries into subsequent states.

Ironically, many suggested that the array of options has contributed to the race’s stability. Voters seem to be gravitating to the few people they know, starving other candidates of support.

“It’s kind of like when you’re at the supermarket and there’s like 30 different cereals and you’re just paralyzed with choices,” said John Lapp, a Democratic strategist who has worked in presidential races. “Some have more sugar, some have more nutrition … and then you just walk away doing your same stuff.”

But there’s still lingering uncertainty. Stung by President Donald Trump’s victory, many Democrats are reluctant to make a firm pick, said Colleen Condon, the party chair in Charleston County, S.C. “No one wants to make the wrong choice.”

While four years ago, most Democrats in Charleston were already committed to Sanders or Hillary Clinton by September, this time around, “you have Sanders people who would also consider Warren, Warren people who might consider Sanders, and Biden people who would consider Harris or Booker,” Condon said.

New Hampshire’s Democratic chairman, Ray Buckley, said most voters in his state, the second in the nominating contest, have not settled on a candidate.

“We’ve all witnessed candidates that have won the New Hampshire primary or Iowa caucus that were at 1 or 2 percent or lower even at Labor Day,” Buckley said. “I don’t think anyone should be counted out yet.”

One immediate change is that more stringent criteria have effectively pushed more than half of the 20-plus-person field to the margins, since only 10 qualified for Thursday’s debate. Sen. Kirsten Gillibrand, Gov. Jay Inslee, and former Gov. John Hickenlooper, among others, quit the race after failing to meet the tougher polling and fund-raising thresholds.

Meredith Kelly, who was Gillibrand’s communications director, said the crowded field made moving ahead all but impossible for her candidate.

“The top three are people that came in with national identities before this race started,” Kelly said. “You need a strong campaign to sustain that position, but overall it’s been difficult to break into that top tier without a base of people who knew that they wanted to support you from the get-go.”

Others who didn’t make the cut face a virtual political death sentence if they also miss the October debate, which could deprive them of attention and the ability to attract donations. “You lose out on the oxygen and then you flat-line, and it’s hard to see people coming back from that,” Lapp said.

“There’s no time for vanity projects," said Jim Manley, a Democratic strategist based in Washington. "A bunch of these people need to give it up so the party can focus on how to beat Donald Trump.”

Even a swath of candidates with seemingly credible qualifications, such as Sens. Booker and Klobuchar and former Housing Secretary Castro, have struggled, despite campaigning for months. Harris and Buttigieg, after fast starts, have stalled.

The hope for those candidates is that a smaller crowd means they get more attention.

Yet, so far, even seemingly big moments, including strong debate performances by Harris, Booker, and Castro and verbal stumbles by Biden, haven’t changed much.

“With all those candidates out there, it’s hard to stay in people’s minds,” said Mike Lux, a strategist who worked for Biden in Iowa in 1988 but has not picked a candidate this time. Like Lapp, he saw people turning to the familiar. “People have had a very traumatic last few years with Trump and they want the comfort of someone, something, that’s familiar and predictable, and I think Biden provides that to a lot of people."

Top Biden campaign aides, despite his consistent polling lead, said they expect a long slog to the nomination.

“We have no expectation that this is going to end quickly after the first states,” a senior adviser said, speaking on condition of anonymity. Another predicted that three or four candidates could stay in the race for a long haul after voting begins.

Biden has consistently led in polls and has defied questions about the depth of his support, with his campaign pointing to his strong leads with African American voters and across a range of geographies, which they say reflects how comfortable Democrats are with his long public record.

But critics have questioned whether there is genuine enthusiasm beneath the polling numbers, a critique that could be tested as the debate sharpens and he faces Warren, who has generated new excitement, and Sanders, who retains a hard-core base.

“If anything, he’s maintaining a precarious lead at the moment,” Aimee Allison, the founder of She the People, a group that focuses on women of color, said of Biden. “In my world, and I work with women of color all over the country, I don’t hear the enthusiasm.”

Bret Niles, who chairs the Democratic Party in Linn County, Iowa’s second largest, said he senses people are still making up their minds among the top four or five candidates. He’s watching to see which campaigns can turn out crowds this fall without the aid of Iowa’s many fairs and pre-organized events.

“If you only get 20 people showing up when you host vs. going to a fair where you have thousands of people already there, that shows something.”

Similarly in Nashua, New Hampshire’s second-largest city, Dave Tencza, a Democratic county chairman, said the race is “probably a little more fluid than the polls suggest. I think there are a lot of people still trying to decide who they are going to support.”

Many of the candidates seem to be planning to stick around. For the annual Blue Jamboree in October, Condon, the Charleston County chair, thought "we’d have maybe four candidates,” especially since they have to pay thousands of dollars for booth space. Instead, 11 have confirmed. So far.