The national fight over an ambitious effort by labor unions to reverse their generation-long decline is about to come to Colorado — and to the race for the U.S. Senate, reports Michael Riley [1].

Sensing a pivotal moment, unions are pouring $300 million nationally into pushing for a Democratic sweep in 2008, perhaps $100 million more than four years ago. And a bigger chunk than usual is going to congressional races, especially the battle for control of the U.S. Senate.