Colorado Amendment 84

Colorado Amendment 84 failed on 3 November 2026; the Associated Press projected its defeat at 10:18pm on polling night. About 63.4% of voters were against on unofficial results at 1:20pm on 4 November, the Sentinel reported. As a constitutional initiative it needed 55% to pass.

The amendment would have required voters to add the last four digits of a Social Security number, a Colorado driver's licence or a Colorado ID card to their mail ballot, on top of the signature check Colorado already runs. A ballot with missing or unmatched details would not count unless the voter fixed it within eight days. It reached the ballot by citizen initiative, backed by the Coalition for American Prosperity and Growth.

In 2024, 92% of Colorado ballots were mail ballots, so the measure would have touched almost every voter. It was one of three mail-ballot ID measures that lost on 3 November, with Arizona and California.