Peabody was a fierce opponent of unions and of any social legislation that limited businesses' right to run their own affairs as they saw fit. The crucial issue in Colorado was the eight-hour day. When the Legislature had enacted a statute limiting the workday in hazardous industries, such as mining and smelting, to eight hours, the Colorado Supreme Court declared it unconstitutional. The voters of Colorado then passed a referendum authorizing the eight-hour day, but the smelter owners and Republican Party fought any efforts to pass a new statute implementing the amendment.