Last Saturday Arn Menconi’s phone started blowing up.

He’s a social justice activist from Carbondale who served two terms on the Eagle County Commission.

Last Saturday was the Democratic Party’s state convention held at the Budweiser Event Center in Loveland. But Menconi wasn’t there because he’s no longer a Democrat. In January, he’d changed his affiliation to become a member of the Green Party. Then, on April 3, he unanimously snagged his new party’s nomination to run for U.S. Senate in Colorado.

Menconi’s phone was going haywire because of the messages rolling in. Something big was going on in Loveland.

“One person sent over a video clip from one of the news stations and said ‘Are you aware of what’s happening?'” Menconi recalled in an interview with The Colorado Independent.

The clip was of current Democratic U.S. Sen. Michael Bennet getting heckled during a convention speech. Chants of “Change your vote” by angry supporters of Bernie Sanders filled the room. Bennet is a superdelegate who supports Hillary Clinton for president. During the March 1 caucuses in Colorado, Bernie bested Clinton by nearly 20 points. Sanders supporters have been putting pressure on superdelegates like Bennet and others in Colorado to back Bernie at the July Democratic National Convention in Philadelphia.

Related: Superdelegate Jared Polis orders takeout. He’s lobbied: ‘Feel the Bern’

Menconi hasn’t yet filed paperwork with the Federal Election Commission, but the candidate says that’s all in the works. (The FEC doesn’t require a candidate to file until they raise or spend $5,000.) He has a website, and he’s been trailing Democracy Now! host Amy Goodman around Colorado this week distributing literature for his campaign.

“He will be on the ballot,” says Andrea Merida, co-chair of the Green Party of Colorado.

What happened to Bennet at the Loveland convention has given Menconi’s bid a boost, he says, confidently proclaiming, “I am almost certain that after Saturday my run has at least five percent of the voters.”

On social media, he started getting messages like this from people at the convention such as Robert Parker who had witnessed the reaction to Bennet:

If you up your campaign a few notches, you can gain a lot of support from the mass of Bernie supporters, the mass of disenfranchised Bennet constituents and the mass of left leaning Independents. They need to hear from you.

Others were calling to ask if they could volunteer on his campaign.

Menconi is a 56-year-old father of two and the founder of SOS Outreach— think Outward Bound, but with skiing and snowboarding— and the author of an audiobook titled “Lied to Death,” in which he interviewed Pentagon Papers whistleblower Daniel Ellsberg. He’s been politically active in Colorado for years, and though he likes Bennet personally— he campaigned for him in 2010— he’s decided to get in the big U.S. Senate race this year and take on the incumbent from the left.

Menconi says he wants to represent “the 99 percent.” He believes Bennet is out of touch with Coloradans. He points to the top campaign donors of the incumbent’s $7.6 million war chest as evidence: Financial firms, lobbyists, Goldman Sachs, law firms.

“We’re run by a global corporate mafia,” Menconi says of modern-day America. “Everyone who I’m talking to believes that we’re run by an oligarchy.”

Menconi is running on a three-pronged platform. He wants to “end endless wars,” make curbing global warming a top priority, get off fossil fuels by 2050, and close the inequality gap.

“Those three issues are not being talked about as number one priorities every single day in Congress because corporations are deciding what the agenda is,” he told The Independent. He also wants to ban fracking.

Just this week, Menconi’s phone started blowing up again.

On Thursday Bennet had officially come out against Amendment 69, a question about whether Colorado should have universal healthcare that will be on the ballot for voters to decide in November.

“I’m very much in favor of Amendment 69,” Menconi says. “We can’t wait for Congress to give people what they want.”

This latest Bennet news, he says, was another boon for his bid.

“Each time this is happening it’s like there’s a stock market crash on Michael Bennet and everybody’s telling me to buy Arn,” he said. “This week alone I’ve picked up five Bernie Sanders volunteers.”

While the candidate is running on the platform of Colorado’s Green Party, whose presidential nominee is Jill Stein, Menconi is also a fan of Sanders.

“I love them both,” he says. “I think what Bernie has done to get the message out about the inequality and the 99 percent is game-changing. This is an election that I haven’t seen since I was a kid in 1968. This is a revolution that’s going on. We are watching the devolution of the two-party system before our eyes. And power will not give up without a fight.”

Menconi will not be the only third-party candidate to see their name on the November ballot in this year’s wild U.S. Senate race. Lily Tang Williams will represent the Libertarian Party. And while Gary Swing, a U.S. Senate hopeful running an offbeat campaign on The Boiling Frog Party platform likely won’t make the ballot, he has filed federal paperwork to run.

As for Menconi, he’s had a good week.

“People started finding me,” he says.