Montanans overwhelmingly approved Initiative 166 on Election Day. The measure requires the state’s congressional delegation to propose an amendment to the United States Constitution that would prohibit corporate contributions and expenditures in Montana elections. Even in Montana, it is unlikely that voters believe this will happen anytime soon. But the law is an expression of outrage about harmful intervention in the state’s campaign system.

The United States Supreme Court in June struck down the state’s Corrupt Practices Act, passed by initiative in 1912. The statute banned corporations from making political expenditures out of their general treasuries. It kept Montana politics free of big money and meddling by outsiders. The conservatives on the court applied their 2010 ruling in the Citizens United case to toss out the law, so corporations can now make unlimited independent expenditures in Montana.

In October, a Federal District Court struck down all of Montana’s political campaign contribution limits, though a federal appeals court soon reinstated the limits.

The big money affecting many state races that most vexes Montanans came from a group of outsiders called American Tradition Partnership, a tax-exempt organization that describes itself as “fighting the radical environmentalist agenda” and refuses to disclose its donors. It brought the lawsuit that led the Supreme Court to strike down the state’s anti-corruption law.