The tally was confirmed when the state’s results from the 2016 presidential race were certified, KMGH-TV of Denver reported at the time.
The 2016 presidential election – in which New York businessman Donald Trump defeated former Secretary of State Hillary Clinton – was the first in which Colorado used a mail-in ballot system, according to the station.
Registered voters received a mail-in ballot weeks before Election Day that November, and were required to either mail back their completed ballot or drop it off at their local county clerk’s office or other specified drop-off location.
But ultimately, a total of 21,408 of the mailed-in or dropped-off ballots were disqualified because of voter-identification issues, the station reported. Of the total rejected ballots, 16,209 were nixed because the voter’s signature couldn’t be verified, 2,606 because the ballot wasn’t signed at all, and 2,593 because the voter’s registration could not be verified.
In the latter case, officials determined that most of the affected voters had either registered through a voter-registration drive, or had registered late.
A total of more than 2.8 million Coloradans voted in the 2016 election, the report said.
According to the website of the Colorado secretary of state’s office, Coloradans who choose to use a mail-in ballot "may need to provide a copy of your ID along with your mail ballot," if they have recently registered for the first time.