(NewsNation) — Dozens of law enforcement agencies are pushing back as Illinois became the ninth state in the nation to ban assault-style weapons.

The Protect Illinois Communities Law makes it illegal to sell or buy assault-style weapons and requires current owners to register them with the state.

Calling it unconstitutional, law enforcement agencies now say they won’t enforce the ban.

As lawsuits are being pursued, the question is, will the new law be upheld by the courts?

A 2022 4th of July parade in Highland Park, Illinois, gave way to terror when a gunman opened fire into the crowd, killing seven and wounding dozens more.

The outcry for change to the state’s gun laws was immediate.

Illinois Gov. J.B. Pritzker spoke out the very same day to lead the charge.

“If you are angry today, I am here to tell you be angry,” Pritzker said. “I’m furious.”

Six months later, with the stroke of a pen, Pritzker made Illinois the ninth state to ban assault-style weapons.

It was a change praised by its supporters, including the speaker of the Illinois House.

“It is time that we protect Illinois communities,” Democratic state Rep. Emanuel “Chris” Welch said. “It is time that we protect Illinois families.”

The law bans the sale or purchase of assault-style weapons, requires current owners to register them with the state and limits the size of magazines.

Failure to comply is a misdemeanor, and possibly a felony for subsequent offenses.

The backlash was swift, some coming from Republican lawmakers as well as sheriff’s offices across the state.

“We have constitutional rights in our country, they protect our freedoms from the government. They are not rights that are given to us by the government,” said Republican state Rep. Patrick Windhorst.

With dozens refusing to enforce the new assault weapons ban, Pritzker addressed those departments directly.

“They will, in fact, do their job or they won’t be in their job,” Pritzker said.

Sheriff Jeff Bullard of Jefferson County is one of many in the state who call the ban unconstitutional.

“I don’t work for him,” he said. “As a matter of fact, I work for about the (35,000) to 37,000 people in Jefferson County; they’re all my boss. And I’m Gov. Pritzker’s boss. He works for me, and he works for the 14-plus million people in this state. And he needs to start realizing that, (and) stop working for special interests and start representing the entire state.”

Bullard said the 2008 case District of Columbia v. Heller, in which the Supreme Court ruled all weapons in common use are protected under the Second Amendment, made it clear.

“There’s not been any new technology to create some kind of new type of firearm rifles, long guns, shotguns, handguns, high-capacity magazines, bump stocks. All these firearms and accessories are in common use, millions of people own them,” Bullard said.

Bullard believes the new law in Illinois will not survive the courts.

Others, meanwhile, question the ban’s effectiveness in creating safer streets.

“The reality is that most of the gun violence that we see in a city like Chicago is not committed with these sorts of long guns in the first place,” said Harvard Law fellow Ian Samuel during an appearance on NewsNation’s “On Balance.” Much of it is committed with handguns — that’s the sort of dark truth about any kind of discussion about American gun policy.”

Still others in support, including those who turned out at the state capitol to ensure it was signed into law, feel the ban is a step in the right direction.

Some of those supporters are Highland Park residents who demanded action after the horror they witnessed on the 4th of July.

“I want to make sure this happens because what my son went through, what my town has lived through.” said Highland Park resident Ashbey Beasley. “To hear the words ‘passed’ is just a remarkable thing.”