The Trump administration is suing Colorado over a law prohibiting a gun magazine that can hold more than 15 rounds of ammunition.

In its lawsuit — filed a day after the U.S. Department of Justice also sued the city of Denver over its ban on “assault weapons” — the federal agency said the state law violates citizens’ Second Amendment rights.

The Colorado law, the DOJ said, “uses politically charged rhetoric to describe the arms it bans.”

“The Magazine Ban’s characterization of these magazines as ‘large capacity’ is a misnomer, because magazines capable of holding more than 15 rounds are, in fact, standard capacity magazines for many popular firearms, including the AR-15 rifle, the most popular rifle in America,” the agency’s lawsuit said.

Colorado Attorney General Phil Weiser vowed to defend what he called “Colorado’s common-sense gun safety law.”

“Using federal civil rights law to put Coloradans at greater risk of gun violence is a dangerous overreach by the Justice Department and this lawsuit turns the mission of the DOJ’s Civil Rights Division on its head,” Weiser said in a news release.

Weiser argued that bans on large-capacity magazines satisfy Second Amendment protections while reducing casualties in mass shootings.

“The state has a duty to protect Colorado residents from gun violence, and I will vigorously defend our state large-capacity magazine limit law from this attack by the Trump Justice Department,” Weiser said.  

Colorado’s ban on high-capacity magazine ban was enacted in 2013 under the state’s Democrat-controlled House and Senate and signed into law by then-Gov. John Hickenlooper.

It came in the wake of the 2012 Aurora theater shooting in which gunman James Holmes opened fire on a crowd of moviegoers, killing 12 people and wounding more than 70 others. One of Holmes weapons was a semi-automatic rifle with a 100-round drum magazine.

The political and legal fallout came swiftly. Gun rights supporters recalled two legislators and another resigned. State sheriffs sued in vain to block the law. 

Magpul Industries, one of the country’s largest producers of ammunition magazines, left Colorado in protest, moving its production, distribution and shipping operations to Cheyenne and its headquarters to Texas.

This is a developing story.

Former Colorado Politics reporter Joey Bunch contributed to this report.