DENVER (AP) — Colorado Democrats advanced aggressive gun-control proposals after a 12-hour marathon debate Friday in a state wrestling with its history of heartbreaking shootings and Western heritage where gun ownership is treasured by many.

Democrats moved forward with new ammunition magazine limits and universal background checks. But they withdrew two of the most controversial pieces of the package, including a gun ban on college campuses and a measure to hold assault-weapon owners liable for damages caused by their weapons.

The Colorado debate is being watched nationally as a bellwether of how far politically moderate states are willing to go with new gun laws in the wake of mass shootings in a suburban Denver movie theater and a Connecticut elementary school. It's also playing out in a state where one of the nation's most high-profile school massacres — the 1999 Columbine High School shootings — took place.