The ad wars are in full swing in the Colorado Senate race, a top-priority race for national Dems, who view this seat as a major pickup opportunity in a Western state that's trending blue.

And here's another sign of just how high-priority this race has become: The League of Conservation voters is pumping nearly $240,000 into the race, running this ad slamming GOP candidate Bob Schaffer as a tool of Big Oil:

The right knows that green issues are big in Colorado -- you might remember the goofy ad we showed you last week from a conservative group, using flowery cartoon imagery to pitch Schaffer as a friend of the environment.