DENVER (AP) -- The last time Colorado enacted gun control measures was in the wake of the 1999 Columbine High School shooting, and once the laws were on the books there was little acrimony.
The state's latest batch of gun control laws ? coming after a gunman's deadly rampage at a suburban Denver movie theater a year ago ? has sparked a struggle over guns that shows little signs of fading. Gun rights advocates are trying to recall two state senators who backed the package, and dozens of GOP county sheriffs are suing to overturn it.
"This is going to remain a political hot potato for Democrats for many, many months," said gun-rights activist Ari Armstrong.
Ironically, in the months after the gunman's shooting spree left 12 people dead and injured 70 others, there was little public discussion of gun control here. The shooting at a midnight showing of the Batman film "The Dark Knight Rises" occurred in a key swing county in one of the most hotly-contested battleground states in last year's presidential election.
But President Barack Obama, seeking re-election, did not bring up gun control in a state that cherishes its western frontier image. Neither did most Colorado Democrats.
It wasn't until December's shooting at a Connecticut elementary school left 20 first-graders and six adults dead that gun control rose in prominence. By March, Colorado became the only state outside the Democratic Party's coastal bases to pass sweeping gun control measures, including universal background checks and a ban on high-capacity magazines.
After the Columbine attack, voters closed a loophole that allowed buyers of firearms at gun shows to evade background checks. In the wake of the Aurora massacre, the prospects for more gun control in this libertarian-minded state seemed shaky at best.
Soon after police say a former neuroscience graduate student named James Holmes, armed with a rifle and a high-capacity magazine able to fire 100 bullets, wreaked his carnage, the Democratic lawmaker whose district is home to the Century 16 movie theater where the shooting took place began drafting gun control bills, hoping Coloradans would be more receptive to them.
They weren't. "There was a sense of political fear," recalled state Rep. Rhonda Fields, who became a legislator after her son and his girlfriend were shot to death in 2005 to stop him from testifying at a murder trial.
In a television interview days after the shooting, Democratic Gov. John Hickenlooper appeared to cast doubt on the effectiveness of new gun control laws.
Despite a push by gun control groups and some relatives of those slain in Aurora, moderators at the presidential debates didn't bring up the topic. Craig Hughes, a top adviser to Obama's Colorado campaign, said it felt inappropriate to raise the issue while emotions were so raw. "The right course here was to not politicize it," he said.
Hickenlooper said he had quiet conversations around the state after that and was struck by wide support for universal background checks.
In November, Democrats won both the state House and Senate as Colorado helped re-elect Obama. And on Dec. 12, Hickenlooper declared that "the time is right" to talk about gun control.
Two days later in Connecticut, Adam Lanza, 20, shot and killed his mother, then drove to Sandy Hook Elementary School and opened fire before killing himself. The attack shocked a country that had grown hardened to mass shootings. Obama vowed an all-out push for gun control.
In Colorado, a similar push was already queued up.
New York City Mayor Michael Bloomberg's gun control organization, Mayors Against Illegal Guns, hired four lobbyists to help push gun bills in Colorado. Vice President Joe Biden called state legislators to urge them to vote for the package. Biden told them that Colorado, with its western traditions, could help set the tone for national gun policy.
To Republicans and gun rights groups, the message was clear. "The Obama administration and these East Coast politicians decided that, as Colorado goes, so goes the rest of the nation,'" said GOP state Rep. Mark Waller.
GOP legislators fought furiously to delay the bills' passage. Hundreds of demonstrators circled the state capitol and packed the legislative chambers. Democrats were confident voters were on their side. They have not lost a presidential, gubernatorial or U.S. Senate race for more than a decade, powered by a combination of a growing Hispanic voting population and an influx of coastal moderates.
"The voices that are the loudest (in protest) are not the ones that determine elections here," Laura Chapin, a Democratic strategist who worked for local gun control groups, said after the bills passed.
For gun rights advocates, the movie theater attack exposed serious problems that Democrats were ignoring: Bans on guns in public areas, and the issue of mental health. Holmes purchased his guns legally but also had seen a psychiatrist who feared he was dangerous.
The Century 16 complex forbade guns. If viewers were armed, gun-rights groups argued, they could have stopped the attack. Advocates also noted that, from the limited information that has become public, some officials at the University of Colorado, Denver, where Holmes studied, may have been warned that he could turn violent.
"Let's not pretend our options are binary ? do nothing or pass more restrictive gun laws," said Armstrong, the gun-rights activist.
The legislature agreed to a $20 million Hickenlooper plan to expand mental health services. But the gun control package got the most attention. The bill banning larger-capacity magazines squeaked through by a single vote in the state Senate.
Meanwhile, Democratic strongholds like New York, Connecticut and California passed some measures, but gun control packages died in Congress and in liberal-leaning states like Minnesota, Oregon, Washington and even Biden's home state, Delaware.
In June, Colorado gun activists collected enough signatures to trigger recall elections for two state senators, including that chamber's president. If Democratic efforts to block them fail, the recall votes could be the first electoral test of post-Sandy Hook gun control. Fifty-four county sheriffs filed a federal lawsuit to strike down the laws as violations of the Second Amendment right to bear arms.
Tom Sullivan, whose son Alex was celebrating his 27th birthday at the theater when he was killed, said he shied away from the gun debate at first. But he went to the state legislature to watch the debate and was at the arguments against action.
"I'm not going to shrug my shoulders," Sullivan said, "and say this is the cost of living in a free society: my son's going to be murdered by a guy with a 100-round magazine walking into a theater on his birthday."
Follow Nicholas Riccardi on Twitter at https://twitter.com/NickRiccardi .