The vote on whether to amend the Colorado constitution to remove a reference to slavery as a punishment for a criminal conviction is tight but not all counties have reported their results yet.
The constitution currently prohibits slavery or involuntary servitude except as punishment for a crime - wording proponents of the amendment say is outdated. They say the amendment is a symbolic statement, and removing the reference to slavery reflects fundamental values of freedom and equality.
Those against the amendment argued it could cause legal uncertainty involving Colorado's prison work programs.
But backers of Amendment T note that 25 other states that do not reference slavery in there constitutions also have prison work and community service programs for inmates.