If Rep. Alec Garnett, D-Denver, hadn’t been sporting his legislative name tag and a suit at Byers Middle School in Denver Tuesday evening, it might not have been obvious he is an elected official. He fit the demographic that showed up to caucus in central Denver to a tee. Young professionals, ages 23 to around 35, dominated the turnout.

Decked out in flannels, thick-framed glasses and political stickers, the mostly young crowd helped carve out a win for Bernie Sanders over Hillary Clinton in a state that had been pegged a must-win Super Tuesday challenge for Sanders.

“The turnout here tonight is amazing,” Garnett told The Colorado Statesman before voting took place. “There are a lot of Bernie supporters here,” he added, noting that even though he caucused for Hillary Clinton, he was excited so many millennials showed up.

Clinton’s experience is what gained Garnett’s support, the lawmaker said.

Garnett said he believed younger Democrats turned out in high numbers because of issues including student loan debt, the increasing cost of childcare and “an economy that doesn’t work for them.” Those are also reasons Garnett said he decided to run for the Legislature in 2014.

“I ran because my values met the values of the district,” he said. “Millennials are the most educated and the most underemployed.”

Garnett’s House District 2 is the youngest district in the state, with one-third of voters younger than 30, so even without their pressing economic concerns, there still likely would have been a preponderance of millennials at the caucus.

Party officials said they expected around 1,000 voters to show up at Byers, but three times that number came through the doors ready to vote with an estimated 3,000 in attendance.

“If this isn’t unprecedented, it’s close,” said Brandon Davis, a caucus organizer. “It meant we had to do some stuff on the fly like reading rules in rooms” rather than to all the Democrats at once.

Ken Hermann, who has been caucusing since the 1970s, said it was the biggest turnout he has ever seen. In his precinct, 218 registered Democrats showed up to cast a vote. The first year Herman caucused, in 1976, he said he distinctly remembered the turnout was 102 Democrats in the same precinct.

From 2003 to 2005 Herman served as the treasurer for the Denver County Democrats.

This time around, there were no undecided voters in his precinct when it came to presidential picks. Six delegates went to Sanders and two went to Clinton.

As of 11:30 p.m., Sanders had won 54 percent of Denver County votes and Clinton had 45.2 percent.

Undecided Democrats were few and far between at Byers.

First-time caucus-goer Jennifer Martinez, 24, said her precinct arrived ready to take a vote. Only two Democrats came hoping to be persuaded, and each candidate received one of their votes.

“There were way more young people that showed up than were expected to, I think,” Martinez said after her precinct finished voting. “I’ll be happy with whoever (makes it to the general election), but I have a little bit more of an agreement on Bernie’s policies. There’s a lot I agree with Hillary, too. If I would have come undecided tonight, the speeches would have probably persuaded me to go with her.”

With 89 percent of the vote reporting statewide, Sanders took the win over Clinton with 58.7 percent. Clinton won 13 of the state’s 64 counties.

— kara@coloradostatesman.com