A proposed ordinance that would give Mayor Ted Wheeler broad powers to restrict where, when and how protesters gather in Portland may not pass constitutional muster if challenged in court, said two constitutional law scholars who reviewed the ordinance at The Oregonian/OregonLive's request.

The proposal, to be debated Thursday afternoon by the City Council, would allow Wheeler to issue orders telling demonstrators where they can protest, for how long and how many people may join in, among other restrictions. Violators would be subject to fines and arrest.

Wheeler has said further regulating protests is a matter of public safety. The idea came about as a direct response to frequent demonstrations in the city that have turned violent – and in particular the Aug. 4 clash between police and protesters, Wheeler and Police Chief Danielle Outlaw told The Oregonian/OregonLive in interviews Wednesday.

"It allows us to put something in place, hopefully before the violence occurs," Outlaw said.

Government officials like the mayor and police chief are limited by law in how they may regulate protests and other forms of free expression. But the U.S. Supreme Court has said governments may adopt reasonable restrictions on the time, place and manner of protests if the limits are narrow, free from bias and there are no alternatives.

However, two legal experts say Wheeler's ordinance gives broad power to him alone to decide how protests may be limited, and it does not offer a method of appeal.

That makes the ordinance "blatantly, dangerously unconstitutional," said Greg Magarian, law professor and free expression scholar at Washington University School of Law. The proposal, Magarian said, gives the mayor "unilateral authority to criminalize constitutionally protected speech before the speech happens, based on wildly subjective criteria."

More: Restrict protests? Where Portland leaders stand

Tim Zick, professor of law at William & Mary Law School, said giving one official vast power over regulating public gatherings "is historically problematic" and makes Wheeler's ordinance "constitutionally vulnerable." Zick, who studies free expression law, referenced Supreme Court cases from the 1930s and '40s striking down laws that allowed a single official to dictate the conditions of public gatherings.

"The court routinely struck those things down because bias is inherent in them," Zick said, given that the laws are based ultimately "on a single individual's notion of what is permissible."

Wheeler is not deterred. He said the city police force – which he is in charge of as police commissioner – will continue to arrest protesters that break the law. And Wheeler said he is "very comfortable" with his attorneys' assessment that the protest restrictions are lawful, though he acknowledged his "100 percent certainty" they will be tested in court if adopted.

Even so, Wheeler may never get that far.

Commissioners Amanda Fritz and Chloe Eudaly are opposed to the restrictions, while Commissioner Dan Saltzman supports the idea. That leaves Commissioner Nick Fish, an attorney, as the swing vote. Fish, who declined to comment Wednesday, has said he will watch Thursday's hearing before making up his mind.

Magarian said Wheeler's ordinance is written with many First Amendment-friendly words and phrases, like "reasonable" and "content-neutral." But that has no legal weight, he said, and doesn't make its enforcement neutral.

"You can call a pig a peacock all day long," Magarian said, "but at the end of the day it's still a pig." He said the system Wheeler wants to install isn't neutral because it puts it "completely in his discretion" whether to restrict protests.

Another legal hiccup for the ordinance, Magarian said, is that it allows Wheeler to consider protesters' histories of violence or the perceived likelihood of violence to decide if restrictions are necessary.

"Predictions about violence becomes problematic," Zick said, "because those predictions can be based on your view of particular groups."

Basing decision about restricting protests on "the government's opinion about what's going to happen tomorrow" or past conduct presents an immediate legal problem, Magarian said.

Portland was previously in legal trouble under similar circumstances, when activist Joe Walsh sued the city and then-Mayor Charlie Hales in 2015. Walsh claimed his weeks-long expulsions from City Council hearings for interrupting the proceedings violated his First Amendment rights, and he prevailed in federal court.

Magarian and Zick said courts sometimes tell governments to enforce existing laws intended to keep the peace rather than create new regulations on public gatherings.

"It's so tempting and easy for government to say, 'We can solve this problem before it ever happens.' But what government is supposed to do is actually find the bad actors and prosecute them under the laws that prohibit bad acts," Magarian said.

– Gordon R. Friedman