Legislators just failed to advance a proposed ban on the sale and transfer of so-called assault weapons in increasingly blue Colorado.

Just days before the session gaveled to a close on Wednesday, the Senate co-sponsor of House Bill 1292 asked for the bill to be set aside without even getting its first committee hearing in the chamber. One day later, the 3-2 Democratic-controlled Senate State, Military, and Veterans Affairs Committee unanimously voted to table it for good. That ended the attempt to ban sales of AR-15s, AK-47s, and numerous other popular guns affected by the proposal.

The bill’s co-sponsor publicly attributed the move to a desire for extra time to have “more conversations” with her fellow Democrats about the measure’s merits beyond the constraints of the legislative session’s final days. In reality, it’s more likely proponents simply did not have the votes to advance a ban on commonly owned semi-automatic firearms. The ban’s unceremonious defeat, in back-to-back sessions no less, is a stark reminder of the uniquely potent politics of hardware restrictions–even in blue-trending Colorado.

That potency in Colorado stems at least in part from the state’s first hardware ban push.

Spurred by the 2012 Aurora theater shooting, lawmakers in 2013 passed a ban on the sale and future possession of ammunition magazines capable of holding more than 15 rounds. That marked the state’s initial major foray into restricting firearms after Republican lawmakers had spent the previous decade passing new gun-rights expansions. It also sparked an immediate backlash that allowed gun-rights supporters to successfully recall two Democratic state senators, including the Senate President, and forced a third to resign to avoid the same fate. Meanwhile, Democrats lost control of the state Senate the following year in the 2014 midterms due partly to that backlash.

That outcome temporarily chastened gun-control advocates in the state, though not for long.

Politically, Colorado has trended in a more progressive direction since those recalls. Democrats currently have more power in the state than at any time since before World War II, holding both the Governor’s mansion and 69 of the state’s 100 legislative seats. Along the way to amassing those historic majorities, Colorado Democrats have quickly come to re-embrace gun restrictions, passing most of the gun-control movement’s biggest priorities over the last five years.

However, that renewed momentum has not yet been enough to capture enough support to pass an assault weapons ban, including among some of the state’s most vocal gun-control advocates. Had the assault weapon bill been scheduled for a proper committee hearing, it would have faced a deciding swing vote from Tom Sullivan, a Democratic Senator and leading figure on gun politics in Colorado who lost his son in the 2012 Aurora theater shooting.

Though Sullivan has backed most gun bills the state has passed in recent years, he expressed skepticism over the efficacy of state-level gun bans and concern that they could revive the backlash that plagued his party in 2013.

“Banning? That doesn’t end well for us,” Sullivan told The Washington Post last year after the previous ban died in a House committee. “And I’m speaking as the father of a son who was murdered by an assault weapon.”

Following the bill’s withdrawal, Sullivan confirmed to the Associated Press that he would have voted “no” had it been put to a vote. He urged his Democratic colleagues to focus on other gun measures instead.

“The narrative is all wrong,” Sullivan said. “That’s what they want you to believe, that it’s assault weapons and schools. It’s not. … It’s suicides and it’s domestic violence.”

Furthermore, Governor Jared Polis (D.) presented another obstacle to the ban’s passage. Though he largely equivocated about his position on the ban as it was working its way through the state House, he eventually expressed relief about its fate in a post-session interview with the editorial board of the Denver Gazette.

“I’ve always been skeptical about that kind of measure,” Polis said, neither confirming nor denying he worked behind the scenes to lobby against it.

This year certainly won’t be the last time gun-control advocates try to get the ban across the finish line in the Centennial State, though. Emboldened by the recent resurgence of state-level assault weapon bans in places like Delaware, Illinois, and Washington, advocates will likely continue to press the issue in trifecta-blue states across the country. Plus, the incremental success of getting the ban further this year than last already has the sponsors of Colorado’s measure gearing up to give it a third try next year.

“I think we had a pretty Herculean effort this year, going from first committee death last year to passing an entire chamber,” State Rep. Tim Hernández told the Colorado Sun. “About 50 days from now, I will be pulling the bill title for next year. And I’m really looking forward to running it next year as well.”

Over the long run, it’s entirely possible that proponents of a ban eventually win the war of attrition against Colorado lawmakers who are currently afraid to take the political hit of signing on to a gun ban. That will almost certainly be true if gun-rights advocates are unable to make any inroads back into political power in the state.

But for now, an assault weapon ban remains a bridge too far for a state that is moving left and running out of other gun-control measures to adopt.