More than 1.5 million Coloradans have cast ballots already in this election, according to data released Monday by the Colorado Secretary of State's office.

That's not quite half of the state's active registered voters.

Statewide, Democratic voters have a nearly 5,000-vote lead over Republican voters.  But unaffiliated voters will play a key role in determining the election: 461,154 unaffiliated voters have already voted this cycle. That's 30.4 percent of all ballots cast.

Unaffiliated voters have participated at a rate not observed before in a Colorado mid-term election, according to an written analysis by Ryan Winger, a consultant with Magellan Strategies, a political research firm.

Read the full story from The Denver Post.