A decision is expected soon on a set of new voting rules that one group calls "unconstitutional".
Colorado Common Cause is suing the Secretary of State's office for two rules: one, requiring all voters to show I.D., and the other, prohibiting absentee voters from requesting provisional ballots.
The group says the rules could keep some eligible voters from voting in this year's elections. But attorneys for the Secretary of State say the rules are necessary to avoid voter fraud.
Election officials add it would cause major problems if they were forced to change rules so close to election day.