Whenever the prospect of managing Last Thursday seems too big or too hard, Michael O'Connor reminds himself of what he calls the most magical moment.

It was 2010. The Northeast Alberta Street art walk had become an all-night party, with visitors peeing and defecating on residents' lawns. About 300 people crowded the Acadian Ballroom to brainstorm solutions.

Among those who rose in defense of Last Thursday was an 8-year-old who said she'd earned $70 playing her violin at the freewheeling street fair.

"She was putting her hopes and dreams out on that street," O'Connor said recently.

The monthly event has only grown bigger and rowdier since 2010. But O'Connor, 29, has a plan to restore Last Thursday to an atmosphere where an 8-year-old street musician can flourish. His solution, coming from an events promoter, might sound surprising: Eliminate about half the visitors.

"It just got too big, which created a problem," he said. "There is a tipping point to good things. It's tough when you've passed that point to come back, but I'm willing to take the risk."

O'Connor's determined risk-taking has already run him afoul of city staff. When he declared last month that he was forming a nonprofit to run the event and collect fees, officials told him he had no authority to do so. His written response: "I don't need your authority."

O'Connor is in for an uphill battle. Returning Last Thursday to its glory days will take time, money and many, many uncomfortable conversations. But the 8-year-old violinist represents the best of what Portland once was, O'Connor says -- and the best of what it can still be.

Last Thursday to Hump Day

Like other activists who have tried to preserve Last Thursday, O'Connor is an artist. He creates sculptures for music festivals, earns about $20 an hour doing special events for Kruger Farms, and recently started designing corn mazes for farmers.

O'Connor grew up in Beaverton, but now lives near Southeast Belmont Street. He has pale blue eyes and a floppy blonde haircut that makes him look like Michael Pitt, the heartthrob indie actor who starred in Hedwig and the Angry Inch and Boardwalk Empire.

He started going to Last Thursday when he lived off Alberta because it was free entertainment.

"You never knew what you would see," he said. "But you knew it was going to be a spectacle every time."

By 2010, vendors and neighbors agreed: The spectacles had become too wild. After the meeting at the Acadian, O'Connor joined a volunteer group called Friends of Last Thursday that wanted to bring some order. But group members didn't get along -- with each other or with city officials. They saw five conflict resolution mediators that year, O'Connor said.

"Nobody had the experience of this level of event production," he said. "It wasn't gearing up for a peaceful resolution."

By 2012, O'Connor felt hopeless.

"He had a hard time being a team player or following through to make an idea happen," said Maquette Reeves, the head of Friends of Last Thursday.

He quit the group and created a new monthly art fair on Belmont Street. The fair, called Hump Day, attracted about 1,500 visitors.

"He always had a new idea and a new way to do something," said Michelle Purvis, a painter who first met O'Connor when she was selling acrylics at Last Thursday.

She followed him to Hump Day. When winter brought rain, O'Connor organized painting parties.

"He had great energy," Purvis said. "Twenty to 50 people would get together and paint and talk about art."

Taking over

Still, O'Connor kept thinking about Last Thursday. The remaining members of Friends of Last Thursday quit in 2013, and the city took over managing the event.

Mayor Charlie Hales ordered the event closed at 9 p.m. this year. In May, staff began writing up people drinking or smoking pot in the right-of-way. In June, city workers began citing musicians for noise violations at the event. Hales has said he is considering fees for some vendors.

O'Connor said the new rules were "causing harm to good people." Vendors wanted a say in what the city charged and how the money would be used.

In July, O'Connor emailed Hales' office to say he was forming a nonprofit, Artists United, that would charge and register vendors.

"I am taking over the responsibility of managing this event whether you give me permission or not," O'Connor wrote Chad Stover, the city's project manager for Last Thursday.

Stover