Hours after urging Democrats to “take a sober look” at the risks of nominating Sen. Bernie Sanders to run against President Donald Trump, centrist candidate Pete Buttigieg pitched himself Saturday at a late-night rally in Denver as the only Democrat who can mend the country’s divisions rather than deepen them.

Speaking to an estimated 8,500 people at the Crowne Plaza Denver Airport Convention Center, the 38-year-old former mayor of South Bend, Indiana, warned that Sanders, who calls himself a democratic socialist, was on the verge of taking an “insurmountable lead” in delegates after his convincing win Saturday in the Nevada caucuses.

Buttigieg, who held a slim delegate lead going into Saturday’s vote, finished a distant third in Nevada, behind Sanders and former Vice President Joe Biden, the early front-runner, whose disappointing finishes in Iowa and New Hampshire has left moderate Democrats scrambling for an alternative to consolidate behind.

“We’ve got a decision to make,” Buttigieg said in Denver, shortly after arriving from Las Vegas. “We’re just a few votes away from Sen. Sanders, who I respect and whose ideals we share but who has a very different approach, getting an insurmountable lead.”

The South Carolina primary on Saturday is the only contest remaining before 14 states, including Colorado, vote on March 3, known as “Super Tuesday,” when more than one-third of delegates to the Democratic National Convention will be awarded. Polls and election forecasters show Sanders is on track to win all but a couple of those contests, with a handful of candidates dividing up the remainder of the vote.

Describing himself as the only candidate who has “beaten Sen. Sanders anywhere in the country during this campaign cycle” – the two finished in a virtual tie in Iowa, with Buttigieg winning more delegates – Buttigieg cast his campaign as the best chance to nominate a Democrat who can win in November. 

“I am here to make a case for a politics that invites everyone in, instead of saying, ‘It’s my way or the highway,'” he said. “I am here to make a case for a politics that aims higher than replacing one form of divisiveness with another, but rather unifies this country, before it is too late.”

Buttigieg and other more moderate candidates caution that Sanders’ call for Medicare for All and other uncompromising proposals risks turning off an electorate ready to deny Trump a second term but unwilling to embrace the Vermont senator’s “revolution.”  

“I believe that we can bring an end to corporate recklessness and rebalance our economy by empowering workers, raising wages, and insisting that those who gain the most must contribute the most in order to keep the American dream going forward,” Buttigieg said in Nevada, shortly before flying to Denver.

“But that is different from Senator Sanders’ vision of capitalism as the root of all evil that would go beyond reform and reorder the economy in ways that most Democrats – not to mention most Americans – don’t support.”

It was Buttigieg’s second visit to Colorado this year, following a small-dollar fundraiser in January at a concert venue in Denver. His husband, former middle school teacher Chasten Buttigieg, met with supporters and attended a fundraiser in Denver last weekend.

In an effort to build on Buttigieg’s momentum following strong showings in the first two nominating contests, his campaign added staff in Colorado this week, bolstering a volunteer-led effort that has been organizing supporters since last spring.

Buttigieg was introduced Saturday night by state Rep. Jeni Arndt, D-Fort Collins, who endorsed him earlier Saturday, along with former Golden Mayor Marjorie Sloan and Wheat Ridge City Councilor Rachel Hultin.

“As a uniter, Pete just makes sense for Colorado and our nation,” Arndt told the crowd, adding that she decided what sets Buttigieg apart is his “enthusiastic energy, broad appeal and the heart and soul of a uniter.”

Buttigieg, a former management consultant and decorated Navy intelligence officer who was deployed to Afghanistan, asked supporters to “imagine what it will feel like the first time the sun comes up over the Rockies and Donald Trump is no longer the president of the United States,” perhaps forgetting that where he stood on Colorado’s Front Range, the sun sets over the Rockies.

“Aren’t you ready to put that corruption behind us? Aren’t you ready to put those tweets behind us?”

He added: “Americans want a president you can turn on the TV, see the news and maybe feel your blood pressure go down a little bit.”

Secretary of State Jena Griswold, a Democrat, joined Buttigieg on stage at one point to ask questions submitted by audience members.

The first came from 9-year-old Zachary Ro of Lone Tree, who asked: “Thank you for being so brave. Would you help me tell the world that I’m gay, too? I want to be brave like you.”

“I don’t think you need a lot of advice from me on bravery. You seem pretty strong,” said Buttigieg, the first openly gay presidential hopeful from a major party, after campaign staffers whisked Ro onto the stage as the crowd chanted “Love means love!”

Buttigieg said it took him a long time come out to anyone, “let alone to go out there and tell the world,” and applauded Ro’s willingness “to come to terms with who you are in a room full of a thousand people, thousands of people you’ve never met.”

Then he offered the youth some advice.

“The first thing is that it won’t always be easy, but that’s OK, because you know who you are. And that’s really important, because when you know who you are, you have a center of gravity that can hold you together when all kinds of chaos is happening around you,” he said. “You’ll never know who’s taking their lead from you, who’s watching you and deciding that they can be a little braver because you have been brave.”

“The last thing I want you to know is, even if I can’t promise it will always be easy, I’m going to be rooting for you, and I think there’s a whole bunch of people here who are going to be rooting for you,” Buttigieg said.

“I think you’ve already got it together, so I’m excited to see what you’re going to do as a leader. Just promise me you won’t run for president until after I’m done, because I think you might be strong competition.”

Colorado has turned into a crossroads for presidential candidates this week as voters began returning mail ballots in the state’s first presidential primary in two decades. For the first time, Colorado’s unaffiliated voters will be able to vote in either of the major parties’ presidential primaries.

Four years ago, Sanders won Colorado’s caucuses by a wide margin over former Secretary of State Hillary Clinton.

Buttigieg is the sixth presidential candidate to campaign in Colorado in the last week, following rallies by Sanders and Sen. Amy Klobuchar of Minnesota, and Trump, who doesn’t face signifiant opposition in the Republican primary. Biden attended a private fundraiser on Monday in Denver, and Rep. Tulsi Gabbard of Hawaii met with voters in Colorado Springs and Boulder.

Sen. Elizabeth Warren of Massachusetts was scheduled to speak at a Sunday afternoon rally in Denver.

The two billionaires running in the Democratic primary, former New York Mayor Mike Bloomberg and California investor Tom Steyer, held events in the state earlier this year, but neither has announced a visit since mail ballots went out.