Trump has called for red flag laws. In Colorado, the gun control policy sparked a backlash.

“My biggest fear for the law is violating someone’s constitutional rights and the potential for placing my deputies in a situation for an encounter with an armed individual,” Reams told CNN.

The sheriff believes the law infringes on the constitutional right to due process and the Fourth Amendment, which protects against unreasonable search and seizure.

“Once you fail to stand up for people’s constitutional rights, then what’s next?” Reams said.

A national model or cautionary tale

Colorado is either a national model for red flag legislation or a cautionary tale, depending on whom you talk to.

Supporters argue that the law is a common sense way to make the state safer and proves it is possible to pass stronger gun laws in a purple state, not just in parts of the country that are deep blue.

“If you can do it in Colorado, you can do it in all 50 states,” said former state senator Mike Johnston, a Democrat who recently dropped out of the Colorado Democratic primary for US Senate. “The Colorado model should be what we do at the federal level to get reasonable gun safety for the whole country.”

Opponents say it violates constitutional rights and will have dangerous consequences, and they argue that the backlash shows just how forcefully a national red flag law would be opposed.

“We’re seeing a very significant pushback in the state and I think you’d see that nationally too,” said Patrick Neville, the Republican minority leader of Colorado’s House of Representatives and a survivor of the Columbine shooting, adding that he believes “it would be a huge mistake” to pass a national red flag law.

How Colorado passed its red flag law

Colorado has seen the horrors of mass shootings firsthand.

In 2012, 12 people were murdered when a gunman opened fire in a movie theater in Aurora, near Denver.

This year, with Democrats in control of both houses of the state legislature, lawmakers passed a red flag law over the objections of gun rights activists. Not a single Republican voted for the bill, which was signed into law by the state’s Democratic governor, Jared Polis.

Under Colorado’s law, a judge can issue an order for a person’s firearms to be temporarily seized without the gun owner first appearing in court. Once the order is granted, a hearing takes place within 14 days and the gun owner and the person who requested the order can both argue their case. A judge can then decide whether or not the individual should be prevented from having access to firearms for up to nearly a year.

Opponents of the law say it infringes on the right to due process.

“The person doesn’t get a chance to defend themselves. They don’t get a chance to plead their case. Their rights are taken before they’re adjudicated,” Reams said.

Supporters, however, argue that the law is fair and protects the due process rights of gun owners.

“Sheriffs execute protection orders every day across the state for domestic violence and civil reasons,” Boulder County Sheriff Joe Pelle, who supports the red flag law, told CNN. “They’re issued. They’re served on the person. Then that person has due process rights afterwards in court. This bill follows that same format.”

Reams and other sheriffs in the state have even gone so far as to say they would be willing to go to jail rather than enforce the law.

“My stance hasn’t changed,” Reams told CNN. “If a judge issues me an order that’s in violation of the Constitution, then I can’t do that, I won’t do it.”

The reaction to Colorado’s red flag law could test the limits of how far gun rights advocates will go to defy gun control laws and may lead to a clash between the sheriffs who object to it and the courts.

“It is unprecedented territory,” Neville said. “You’ll probably see a standoff between the counties, the commissioners who really control the funding … and the sheriffs too and probably against the courts.”

Democratic Rep. Jason Crow, who represents the district that includes Aurora, told CNN that the Second Amendment sanctuary movement in Colorado is “absolutely concerning.”

“Local law enforcement and local leaders have to follow the rules. They have to follow the laws,” Crow said, adding “We will expect them to do that.”

A legal challenge and recall efforts over the law

That’s not the only resistance the red flag law has met.

A series of recall efforts were launched in an attempt to oust Democratic elected officials who supported the law, but the efforts have not been successful.

This isn’t the first time that lawmakers have faced recall attempts in Colorado over gun legislation.

But supporters of the state’s red flag law argue that gun-rights activists have lost ground in the state.

“Absolutely the tide is turning,” Sullivan said. “The regular, law abiding citizen here in the state of Colorado is getting fed up with the bullies and the extremists and they are speaking out against it.”

Additional legal challenges are expected once the law takes effect in January 2020.

“We’re trying to fight it every step we can,” said Neville, who joined Rocky Mountain Gun Owners in bringing the lawsuit.

Sullivan is confident, however, that attempts to overturn the law will not succeed.

“They have taken this to court on a number of occasions in other states with red flag laws and each time it has been thrown out,” Sullivan said. “This is a constitutional law.”

According to the Giffords Law Center, which advocates for stronger gun laws, there have not been any successful legal challenges of extreme risk protection laws in other states.

What’s next in Washington and in Colorado

In Washington, lawmakers are facing pressure to take action on gun violence now that they have returned from their summer recess period.

“We must make sure that those judged to pose a grave risk to public safety do not have access to firearms and that if they do, those firearms can be taken through rapid due process,” Trump said in remarks from the White House. “That is why I have called for red flag laws, also known as extreme risk protection orders.”

Some Republicans in the GOP-controlled Senate, where any gun legislation would need to pass to make it to the President’s desk, have expressed support for legislation to encourage states to adopt red flag laws.

Some Republican senators, however, have voiced skepticism that Congress will pass red flag legislation.

With lawmakers back in Washington, the pressure is sure to intensify on all sides.

Dudley Brown, the president of the National Association for Gun Rights and executive director of Rocky Mountain Gun Owners, said that if he had an opportunity to speak to the President he would warn him that any push for stricter background checks or red flag laws could cost him the White House in 2020.

“Mr. President, if you want to devise a way to lose the 2020 elections, go against your base and support these two gun controls or any others,” Brown said in an interview with CNN.

Sullivan, of course, has a very different message and hopes that Congress will act to pass a national red flag law and universal background checks.

“Families have been pleading for help, law enforcement is pleading with their elected officials to give them the tools that they need to save lives and a red flag law is one of the tools that they need,” he said.

“This is the right thing to do,” Sullivan said. “If you do the work, if you talk to people and have a belief in this, then things can change.”