Five gun bills debated in committee at the Colorado Capitol on Monday night were voted down.
The Democrat-led state House State, Veterans, and Military Affairs committee heard a package of Republican-sponsored gun bills.
One bill would allow concealed carry on public school grounds.
Another would repeal gun magazine limits that were adopted after the 2012 mass shootings at an Aurora movie theater and at Sandy Hook Elementary School in Connecticut.
A third bill would extend the right to use deadly force to business owners and employees.
After seven hours of debate, all five bills were voted down.
Survivors and gun-control proponents testified against the measures, including Tom Mauser, whose son Daniel was killed in the 1999 Columbine shootings.
"Attempts to gut Colorado’s sensible gun safety laws have been an annual exercise in futility ever since the laws were expanded in 2013," the House Democrats said in a statement sent to Denver7. "Noteworthy this year is the absence of any effort to repeal the 2013 law closing the background checks loophole in Colorado, which has been so effective and popular – and with no infringement of Second Amendment rights – that even the 'no compromise' crowd has given up."
"This is another complete failure on the part of Colorado blueprint Democrats to protect the natural rights of Coloradans," said Rep. Steve Humphrey (R-Eaton). "I am disappointed that they haven't listened and learned to put the needs of the people ahead of their political agendas."
"These bills would have protected the rights of Coloradans to defend their property and loved ones," said Rep. Perry Buck (R-Windsor). "I am upset that Democrats do not consider upholding the Constitution a priority."