Colorado voters successfully recalled state Senators Morse and Giron back in September (bonus sad clown tears here). While there were other pressing issues, their support for gun control was the most glaring to their constituents.
Despite outspending the NRA and local groups by a wide margin, Michael Bloomberg was unable to protect either of them. His promises (and threats) that gun control was a safe vote suddenly rang very hollow. Following those recalls, Governor Hickenlooper meekly asked gun control groups to stay out of Colorado.
Rather than face a recall election, Hudak has voluntarily resigned. From her letter:
Most Coloradans believe that the convenience of high-capacity ammunition magazines is less important than saving lives in tragedies like Sandy Hook, Aurora and Columbine. That’s why I sponsored SB 13-197, a bill that takes guns out of the hands of domestic abusers. (…) By resigning, I am protecting these important new laws.
She doesn't bother to claim that she was outspent by "outside interests" since local unions outspent recall petitioners by a 2:1 ratio. Her problem is her arrogance and blindness to the wants of her constituents.
Her resignation before the recall means her party can appoint an interim successor, rather than risking an election. As such, the Colorado Senate keeps its Democratic majority. Nonetheless, this is a win for gun rights.