The protests of 2016, against pipelines and police shootings and a presidential candidate, have sparked lawmakers in eight states to consider bills boosting penalties for unlawful demonstrations. They include one that would protect drivers who “unintentionally” run over activists blocking roads and another aimed at forcing protesters to pay up to three times the costs of any damage they caused.

In Washington state, a lawmaker termed some protests “economic terrorism” and introduced a bill that would permit judges to tack on an additional year in jail to a sentence if the protester was “attempting to or causing an economic disruption.”

In Minnesota, a person convicted of participating or being present at “an unlawful assembly” could be held liable for costs incurred by police and other public agencies.

And in Indiana, a proposed law would direct police encountering a mass traffic obstruction to clear the road by “any means necessary,” echoing a phrase made famous by Malcolm X during the 1960s civil rights movement.

“We’re not trying to restrict people’s right to protest peaceably,” said Iowa state Sen. Jake Chapman (R), in comments similar to those by legislators involved with each of the measures. He introduced his bill, increasing the penalty for blocking a high-speed highway from a misdemeanor to a felony punishable by up to five years in prison, after an anti-Donald Trump protest by high school students in November blocked one direction of Interstate 80 for 30 minutes. “But there’s appropriate places and times. And the interstate is not one of those places. . . . Right now they’re going to get charged with jaywalking and fined $35. That doesn’t fit the crime, in my opinion.”

Demonstrators block Interstate 94 during a protest for slain black motorist Philando Castile in Falcon Heights, Minn., in July. (Jabin Botsford/The Washington Post)

Lee Rowland, a senior staff attorney with the American Civil Liberties Union specializing in First Amendment issues, said she had seen occasional attempts to crack down on protests over the years.

“But I’ve never seen a coordinated attack on protesters’ rights anywhere near this scale,” Rowland said. “What all of these bills have in common is they may be dressed up as being about obstruction or public safety, but make no mistake about it: These are about suppressing protests with draconian penalties so that the average person would think twice before getting out on the street and making their voice heard.”

Cody Hall, a member of the Lakota tribe who was arrested while protesting the Dakota Access pipeline in North Dakota, said the measures would set back civil rights.

“We’re going backwards 60 years,” Hall said. “It’s okay to use your vehicle to run down protesters? How is it that protesters are not considered human beings? It’s my free speech — we can do this. You’re going to get people who say, ‘Hey, the law backs us. We can run people over.’ ”

None of the measures have passed yet. All have been proposed by Republicans. Rowland called them “undoubtedly unconstitutional” and said the ACLU would challenge any which are signed into law.

But their sponsors said they reflect the public’s frustration with prolonged, disruptive protests, such as those at the Dakota Access pipeline, where demonstrators have camped for months, and the Black Lives Matter protests around the Minneapolis area, which have at times closed parts of the famed Mall of America.

Most states have laws restricting protests at funerals, after protests outside military services prompted outrage, and federal law and some states regulate protests near abortion clinics. But Jonathan Griffin of the National Conference of State Legislatures said he had not seen such a spate of bills addressing protests in general.

The pending bills mostly were not created as a response to protests against President Trump, the sponsors said. But as America’s political debate becomes more fractious, as seen by last weekend’s spontaneous demonstrations against Trump’s new immigration executive order, the proposals take on new meaning.

Peaceful protests have occurred throughout history, noted Tamara Madensen, a criminal justice professor at the University of Nevada at Las Vegas, who studies crowd dynamics and protests.

“Marching in the street is symbolic,” Madensen said. “Smart police have learned that the best way to police a public protest is to facilitate it. In doing so, the focus should always be on protecting constitutional rights and public safety and not just enforcing laws for the sake of enforcing laws.”

Laws targeting protesters “need to be crafted in a manner that allows police to address the very few who wreak havoc, but the laws should also be there for people who want to spread their legitimate message and exercise their constitutional rights,” she said.

Some feel the protesters frequently go too far.

“In Minnesota,” said state Rep. Nick Zerwas, “blocking freeways and closing down the airport have become the go-to move for the protester class.” His bill would make someone who is convicted of participating or being present at an unlawful assembly “civilly liable for public safety response costs.”

Zerwas pointed to the recent Women’s March, which drew 100,000 people to Minneapolis, as an example of non-intrusive protests without any arrests or closures.

“My point is,” Zerwas said, “you don’t have free speech rights for the middle of the freeway. If you block the freeway, go to jail. And when you get out of jail, you should get a bill for riot.”

The wave of new protest-related bills “is a sign, not of any coordination” between lawmakers in various states, Zerwas said. “I think that’s the electorate talking to their elected representatives saying they’re sick and tired of that nonsense,” he said.

The standing protest of the Dakota Access Pipeline in North Dakota began last April and has annoyed many residents because it involves people interfering with traffic on a nearby highway, Rep. Keith Kempenich said. He said the protest was located 40 miles from any population center, so demonstrators were not going to get any attention unless they took dramatic action. In one episode, traffic on the 65-mph road was slowed to a crawl, ensnaring some of Kempenich’s family members. “At that point, I thought, ‘this isn’t right,’ ” he said.

He introduced a bill, which states that any driver “who unintentionally causes injury or death to an individual obstructing vehicular traffic on a public road . . . is not guilty of an offense.” Kempenich said, “The First Amendment works both ways. You’ve got the right to assemble peacefully and legally. The other side of it is other people who don’t want to participate. . . . I just intended it to keep people that didn’t want to be involved in this from being drawn into it.”

Similar sentiments about keeping the roads clear, particularly for public safety and emergency vehicles, were voiced by officials in Iowa, Minnesota and Indiana. “The object of this measure is very simple,” said state Sen. Jim Tomes of Indiana in a statement about his bill directing law enforcement to use “any means necessary” to clear roads. “An ambulance needs to be able to get to an individual who is having a heart attack, and law enforcement needs to be able to respond to a call to attend to someone who needs help.”

Tomes declined to be interviewed about the law’s language echoing the phrase made famous by Malcolm X.

In Washington state and Colorado, lawmakers filed bills after activists targeted oil refineries to protest the continued use of fossil fuels. Colorado’s bill would make the crime of tampering with oil or gas gathering equipment a felony instead of a misdemeanor. Washington state Sen. Doug Ericksen introduced a bill that would allow a judge to increase jail time by six months for a gross misdemeanor and 12 months for a felony for those involved in “economic disruption,” and would allow those convicted of organizing or funding such protests to be charged three times the actual damage caused.

“That’s the most important part of the bill,” said Ericksen, who was deputy director of the Trump campaign in Washington. “If you’re organizing a protest that’s done lawfully, there’s no problem.”

In Missouri, legislators are considering a bill that would make it illegal to conceal one’s identity “by the means of a robe, mask or other disguise” while committing the crime of unlawful assembly. And in North Carolina, an incident which occurred in Washington shortly after the inauguration caused a legislator to say he would introduce a bill making it a crime to “threaten, intimidate or retaliate against a present or former North Carolina official in the course of, or on account of, the performance of his or her duties.”

Sen. Dan Bishop, who also authored the controversial “bathroom bill,” was outraged by a video of protesters who cornered former Gov. Pat McCrory and shouted “Shame on you!” for three minutes. “This is dangerous,” Bishop said on his website. He said former North Carolina governors “never faced riotous mobs in their post-service, private lives, without personal security.” His bill has not yet been introduced.

Activist DeRay Mckesson, a member of the Black Lives Matter movement, said the proposals were all aimed at muzzling opposition. “People in power benefit from silencing dissent, and these laws function to silence those willing to challenge those in power,” he said. “If passed, these laws would penalize citizens who are willing to speak out against injustice. . . . Protest is a core American right.”