Wall Street Journal:

The progressive campaign to turn Colorado into the California of the Mountain West took a leap forward last week as Democrats in the Rocky Mountain State advanced a bill to repeal their right-to-work-lite law.

During the early 20th century, Colorado was fraught with labor militancy. To cool tensions, lawmakers in 1943 enacted the Labor Peace Act, which requires 75% of workers at a work site to approve so-called “security agreements” that compel them to pay union dues to support collective bargaining.

Congress soon afterwards passed the Taft-Hartley Act, which blessed state right-to-work laws that bar workers from being required to join unions or pay dues. Colorado’s Labor Peace Act shares the same goal as right-to-work laws—that is, preventing workers from being forced to finance unions they don’t support.

The law is one reason Colorado’s labor environment more resembles that of the 26 right-to-work states and is more attractive to employers than leftwing union bastions. About 7.7% of Colorado workers belong to a union, which is about half as much as in California (14.5%) and only slightly more than in Iowa (6.4%), Alabama (6.6%) and Nebraska (6.8%).

Unions have long sought to repeal Colorado’s law, and they nearly succeeded in 2007 until a courageous veto by then Democratic Gov. Bill Ritter. In his veto message, Mr. Ritter noted that the law threatened to damage the state’s “ability to attract new business to Colorado” and “to create new economic opportunity for all.”