Colorado active voters are now at three million, with total active and inactive (didn’t vote in last presidential election or in 2014 or not newly registered), at 3.6 million. That reflects an increase of 200,000 active voters since December 2015.
In the 2012 presidential election, Barack Obama, Mitt Romney and a few third-party candidates (Libertarian, Green, etc.) attracted 2.8 million voters. There were 3.7 million registered voters, with Democrats and Republicans tied at 32 percent and unaffiliated, the largest bloc, at 37 percent.
In the Cory Gardner and Mark Udall senate race of 2014, a total of 2 million participated. Assuming at least 3 million voters in 2016, it reflects an increase of 50 percent over the off-year senate election and about a quarter million more than the last presidential election.