On the other side, the recall effort was supported by the National Rifle Association but seems to have been driven by grassroots fervour. Most notably the result will disappoint the Mayor of New York, Michael Bloomberg, founder of Mayors Against Illegal Guns, who wrote a personal cheque for US$350,000.
"[We are] proud to have stood with the men and women in Colorado who sent a clear message that their second amendment rights are not for sale," an NRA spokesman told the Denver Post.
Ousted were Senate President John Morse and Senator Angela Giron, who supported laws to restrict the size of bullet magazines and tighten checks for private guns sales signed by Governor John Hickenlooper earlier this year.
Morse and Giron will be replaced by two Republicans, councilman Bernie Herpin and former police officer George Rivera, who opposed the law.
Recall elections have been allowed in Colorado since 1912 but this was the first time such a campaign had successfully been used. Morse said he had no regrets.
"I said at the time if it costs me my political career, so be it," he said.
"That's nothing compared to what the families of [gun violence] victims go through every single day. We did the right thing."
- Independent, AP