SEATTLE — Elizabeth Warren has the crowds. Joe Biden has the lead.

The split-screen story of one of the most intriguing matchups of the Democratic presidential primary is unfolding in a glaring contrast of style and substance.

On Sunday, Warren stood on the biggest stage of her presidential campaign for a rally here that drew an estimated 15,000 people — eclipsing an estimated 12,000-person event she held in Minnesota earlier in the week, according to her campaign. Across the country, Biden presided over a series of intimate, subdued events in New Hampshire and Iowa, hosting crowds that numbered in the low hundreds.

Warren roused her supporters with calls for “big, structural change,” and the crowd roared with chants of “Two cents! Two cents” while waving two fingers in the air as Warren discussed her 2 percent "wealth tax.” Biden pounded away at President Donald Trump, his campaign subtly and overtly reminding voters that polls consistently show him as the party's best general election candidate and the primary’s front-runner.

The parallel displays by two of the three leading Democratic candidates offered a possible preview of the collision course looming if Biden and Warren maintain their current trajectory. It would be a clash of opposites: the progressive firebrand against the establishment favorite; the cerebral candidate of big, bold plans vs. the elder statesman offering himself as a safe haven for people who simply want a return to pre-Trump normalcy.

With Warren rising in the polls and Biden’s lead narrowing since late spring, her message is igniting progressives.

“Warren is on fire,” said Howard Dean, who in 2004 ran a Warren-like campaign as the unapologetic progressive outsider.

But Dean flamed out against John Kerry 15 years ago, reflecting the penchant of primary voters to nominate the safe choice to challenge the president of the opposition party running for reelection. And Dean, who is neutral in the race, acknowledged that Biden could benefit from similar circumstances in this cycle.

The primary, he said, will come down to “the element in the party that wants real change and the element that just wants to beat Trump.” Right now, Democrats are more focused on beating Trump, and those voters favor Biden most.

But today’s Democratic Party is far more progressive and Warren is far better organized than he was in 2004, he added.

“There has been a huge sea change,” Dean said. Democratic voters are “much more [people] of color and they’re much more female and they’re young.” And Biden is no Kerry, he said: “Biden is the old establishment, but he has cred because he was Obama’s vice president.”

Along the bucolic shores of Loon Lake in New Hampshire after a Biden speech Friday, former state House candidate John Streeter summed up the contrast between the two candidates.

“Warren is a rock star,” Streeter said.

And Biden?

“Joe Biden is a rock,” Streeter said. “We know him.”

In light of Biden’s standing atop the polls and the number of endorsements of influential Democrats, his campaign has grown weary as reporters and critics — including Trump — use crowd size as a metric to judge him.

“Are we worried about Elizabeth Warren’s crowd size? No, we’re not. I get it and I understand that it’s an easy metric to measure or to view,” said Pete Kavanaugh, Biden’s deputy campaign manager and point man in the early states.

“Some people — not local press but national press — are wondering, ‘Why did you have only 130 people on Wednesday in Prole [in Iowa].’ Well, it’s a town of 900 people,” Kavanaugh said. “We think it has strategic importance in the caucus. We’re not going to Cedar Rapids and Des Moines every trip. I get it. It would be lovely to have a crowd of 1,000 people every day. But it does not matter on Feb. 3,” the date of the state's caucuses.

Still, Biden’s advisers are taking Warren seriously, and others on the team have privately acknowledged they see Warren as his strongest challenger of the nearly two dozen Democratic candidates.

Where Biden is dominating with traditional campaign donors, Warren is building a small-dollar money machine that makes her more of a financial threat than many had anticipated.

In June, Warren raised $7.8 million from 320,000 donations, compared with Biden’s $2.2 million from 111,000 donations, according to data from ActBlue, the online fundraising tool. (That is the most recent information available from the site.) Their small-dollar performances have been going in opposite directions, with Biden’s best days coming the week of his launch and Warren gaining steam over time.

But while Biden, for now, has the centrist, establishment path largely to himself, Warren still has Bernie Sanders in her progressive lane. Sanders has an even bigger small-dollar army, and also drew big crowds this week in Sacramento, Calif. and Louisville, Ky. The two are projecting similar messages, railing against the ultra-wealthy, asking people to join a broader movement, and subtly hitting Biden by warning against incrementalism.

Sanders isn’t viewed by Biden’s campaign as having as much room to grow as Warren. But Biden’s camp does see the continued strength of Warren and Sanders as an advantage, each limiting the other’s ability to expand their own base of support. Sanders’ campaign thinks he can eat into Biden’s support because of demographic overlap between their voters.

The two African-American candidates in the race, Kamala Harris and Cory Booker, have so far been unable to chip away at Biden’s solid lead among black voters, who give Biden a huge advantage especially in South Carolina and other Southern states.

Biden’s campaign also thinks his core message — prioritizing beating Trump and referring nostalgically to President Obama — resonates powerfully across the Democratic electorate.

“We have to reach beyond our party. We have to unify the country. We have to restore the soul of the nation,” Biden said Saturday to a crowd of about 300 at Keene State College in New Hampshire.

“We have to be a nation that values honesty and decency, treating everyone with respect and dignity, giving everyone a fair shot and leaving no one behind, giving hate no safe harbor.”

In response to an audience question about how she’d take on Trump, Warren said, “We’re not gonna win this by just saying, ‘not Trump.’” She added that “[w]hat is ugly, we can call it out. But that’s not enough. It’s not enough to be ‘not Trump.’”

Warren and Biden also diverge on style.

He meanders off-message and sometimes flubs his facts. At his first stop at Dartmouth College over the weekend, Biden veered into a discussion about the instability of the 1960s and early 1970s. But he mistakenly gave the wrong number of fatalities during the Kent State shootings, unexpectedly wondered aloud about what would have happened if Obama had been assassinated and confused being in New Hampshire with being in Vermont.

On the stump, Warren is resolutely on message. Where Biden is running as an extension of Obama’s presidency, Warren seldom mentions the last Democratic president. Her campaign markets her as the leader of a movement, selling “I’m a Warren Democrat” T-shirts. Some of her organizers invoke the Hamilton musical lyric, “This is not a moment, it’s the movement.”

Liberal hot spots like Seattle guarantee big, attention-drawing crowds as well. As at her other speeches, Warren on Sunday framed her campaign as an opportunity for Democrats to advance a cause, invoking the earlier efforts of suffragettes, union organizers, and civil rights foot soldiers.

“But they didn’t quit. They got organized. They built a grass-roots movement, they persisted, and they changed the course of American history,” she said. “This is our moment in American history. Dream big. Fight hard. Let’s win.”

Marc Caputo reported from New Hampshire and Alex Thompson from Seattle. Maggie Severns contributed to this report.