Last year, Gov. Scott Walker of Wisconsin and the Republican-controlled State Legislature approved the world’s largest open-pit iron ore mine, a gash in the northern part of the state that could be as long as 21 miles, a half-mile wide and 1,000 feet deep.

The mine legislation was bad enough from an environmental point of view: It allows the operator to fill streams with mine waste, eliminates public hearings and reduces the taxes the operator would have to pay.

It turns out to be even more shocking from an ethical viewpoint. Newly released documents show that the mine operator, Gogebic Taconite, secretly gave $700,000 to a political group that was helping the governor win a 2012 recall election. Mr. Walker had urged big corporations to give unlimited amounts, without fear of public disclosure, and many companies that wanted favors from the state happily obliged. Once the recall failed, the favors began to flow, even at the expense of the state’s natural resources.

The group that received the money, along with millions of dollars in other donations, was the Wisconsin Club for Growth, an “independent” conservative spending organization that state prosecutors say was actually controlled by R.J. Johnson, one of Mr. Walker’s closest campaign aides. Mr. Walker and his aides brazenly violated state campaign finance regulations barring coordination between independent groups and candidate campaigns, first by rounding up the money and then by telling the groups how to spend it.