The signs all said “Bernie,” but the senior senator from Vermont wanted the focus to be on the thousands of people holding them.

“We are going to put together a grassroots movement that transforms our country,” Senator Bernie Sanders, a leading contender for the 2020 Democratic presidential nomination, told the crowd at Civic Center Park on Monday, September 9. “The message of our campaign is us, not me. No president — not Bernie Sanders or anyone else — can do it alone."

In a speech that lasted a little over a half-hour, Sanders outlined an ambitious policy agenda that included a single-payer, Medicare for All health system; free public college and the cancellation of student debt; and a Green New Deal to fight climate change and accelerate the transition to renewable energy.

“This is an unprecedented moment in American history,” Sanders said. “What we are fighting for is to end the drift toward oligarchy and create an economy that works for all.”

Polls show that Sanders, who defeated Hillary Clinton in Colorado’s 2016 Democratic caucuses, holds a narrow lead over former vice president Joe Biden and Massachusetts Senator Elizabeth Warren in Colorado’s 2020 primary, which will be held on March 3. His campaign estimated Monday night’s crowd at 10,000 strong.

Rally-goers cheered as Sanders delivered a series of stinging rebukes to Wall Street, health insurers, the fossil fuel industry and other ”corporate elites."

“The issue is not left versus right, it’s corporate power versus the people in this country,” says activist Michele Swenson, a longtime Sanders supporter. “Bernie understands that more than anybody. Policy is written by and for corporate power.”

Sanders has been criticized by moderate Democrats — including two prominent Coloradans, former governor John Hickenlooper and Senator Michael Bennet — for the scale and scope of his agenda. His Medicare for All proposal, for instance, would end private health coverage and transition every American into a government-run insurance program, a move that critics say would be too disruptive. But his supporters, especially young people, argue that ambitious policies like these are necessary.

“I think his somewhat radical ideas — you have to shoot higher to land somewhere quote-unquote reasonable in everybody else’s mind,” says Olivia Marshall, who was attending her first Sanders campaign event. “I don’t think he’s crazy. His ideas are actually quite logical.”

Sanders and nine other primary candidates will participate in another televised debate on September 12, in Houston, and are expected to continue debating monthly until voting begins with the Iowa caucuses in early February. Some attendees of Monday's rally said that despite their enthusiasm for Sanders, they're keeping an open mind.

“I was fully in for Bernie in 2016,” says Denver resident Sunnie Pawley. “I guess I’m in this year, but I would say I’m still undecided, because there are some really good candidates.”

The crowded Democratic primary field is united in its opposition to President Donald Trump. But while Sanders had plenty of harsh words for a man he called a "pathological liar" and a "bigot," he made it clear to Monday's crowd that his campaign is about more than just returning a Democrat to the White House.

“I’m here in Denver asking your support for something more than just defeating Trump,” Sanders said. “I’m asking you to work with me to help transform this county and create an economy and a government that works for all of us, not just the 1 percent.”

“This is it, guys,” Pilar Chapa, state director for the Sanders campaign in Colorado, told the crowd. “This is a revolution, this is a movement, and we are counting on you.”