Another star, besides Gardner, has been Scott Gessler who won the Secretary of State position. (He's running for governor in this election.)
To understand it all, it starts with Fred Barnes 2008 article on the Colorado Model. Here.
There's a quick read of how it happened from a 2010 Red State. Here.
The book mentioned is a good read, more in-depth, and shows how other states Democrats are working behind the scenes, here.
Colorado Progressive Democrats do have a good Get Out the Vote effort and it cannot be ignored. Colorado Republicans can win but only if we are united behind a specific candidate, which hasn't happened in some of our past elections. Democrats here work hard to depress the vote and split our tickets.
They do it in Montana too. They smile and try to run as Not Too Conservative and then they lose.
Good comments, and you are correct about Gessler being in the same category as Gardner.
“Colorado Republicans can win but only if we are united behind a specific candidate”
And to do that, it first requires we have sterling candidates like Gardner and Gessler, instead ones like that nutjob, Dan Maes.