They came early and they came prepared.

For months, Andrew Landsiedel, Adam Redding-Kaufman and Macklin Thornton had been protesting a proposed city ordinance that would fine adults who knowingly provided minors with a place to drink. This week, the three Laguna Beach High School students took center stage in a packed City Council meeting to argue against the measure.

Their opposition was formidable — school officials, a deputy district attorney, medical doctors, Mothers Against Drunk Driving, the local PTA and even a tearful father whose only son was killed by a drunk driver. To make matters worse, it was finals week at school and seniors had taken a trip that day to Knotts’ Berry Farm. There would be meager backup.

Yet Thornton, who wore a crisp suit, remained confident.

“We have facts,” said the UC Berkeley-bound 18-year-old. “They have anecdotes.”

The boys had been honing their arguments since the issue first came up as a topic of discussion among their classmates at the Model United Nations.

The ordinance would be redundant, they told the council Tuesday night, because laws covering such offenses already exist. They said there were also questions of civil liberties and the risk that young people would be driven to drink in parks and at the beach. The proposed law might also discourage people from calling 911 for fear of being fined.

If anything, they argued, the city should pursue education rather than punishment.

“I beg you not to look at us as children, but as young adults,” said Landsiedel, a sophomore. “We are not encouraging teen drinking, we are not encouraging partying. We merely seek a solution to the problem that will be effective and cause youth to work with police rather than against them.”

Redding-Kaufman donned a Cal Poly San Luis Obispo hoodie before he spoke to indicate where he’s going to school in the fall.

“Law by law, we are discouraging minors from going to adults when they need help,” Redding-Kaufman, 18, said. “Does our city want to communicate with minors, or punish them.... Voting no on this ordinance will not convey that this city condones underage drinking, but rather, it’d be a step towards communicating between minors and adults.”

A number of those who turned out in support of the proposed ordinance commended the teens for their civic involvement but questioned why the ordinance wasn’t already on the books. They listed the dangers of alcohol — causing automobile accidents and leading to sexual assault. Health experts spoke of addiction, and a prosecutor warned that teenage drinking is a “common thread in many of our cases.”

Mary Beth Griffin of Mothers Against Drunk Driving offered unequivocal support for the measure because it would be another “arrow in the quiver for law enforcement” to confront the problem of underage drinking in Orange County.

As the public comments dragged on for hours, the discourse became barbed at times. Opponents trashed the proposal as “sloppy” and “poorly written.” One mother even labeled it “Talibanesque.”

After one recent UC Santa Barbara graduate said he had been at a party where attendees avoided calling 911 when someone passed out, a school official said that he showed a “disturbing lack of moral and ethical character.”

One cluster of women scoffed at the teens’ remarks, rolling their eyes and shaking their heads as the young people spoke.

After the crowd had its say, council members had their turn to talk. They shared some of the teens’ concerns. They parsed the language of the proposed ordinance — what does “knowingly” mean exactly? — and raised plenty of hypotheticals.

To the chagrin of many in the crowd, they held off on a vote. Instead, they said they would wait until November to allow for more community input.

The teens hailed this as a victory, saying it would give them the chance to shape something better for the community.

“We have a chance here to really do something,” said Councilwoman Toni Iseman. “And the conversation is the best part.”

rick.rojas@latimes.com