Paul Blumenthal for HuffPo:

This was certainly the case in Sheehy’s 2012 race, although the public didn’t know it at the time.

The Montana Growth Network was launched that year by Jason Priest and Ed Walker, then both Republican state senators. It went on to spend $900,000 on the state Supreme Court race, more money than the Sheehy and McKinnon campaigns combined. Because the group was organized as a 501(c)(4) nonprofit under the federal tax code, it was not required to disclose its donors. Any interest those donors had in the race was obscured, as was any potential conflict that the group’s favored candidate, McKinnon, might later face on the bench.

Three years passed before the identities of the billionaire businessmen funding the ads came to light, following an investigation by Montana’s Commissioner of Political Practices. The December 2015 probe found that the Montana Growth Network had violated state election laws and forced the nonprofit to disclose its funders.

The largest portion of the group’s money came from two of America’s richest men. San Francisco billionaire Charles Schwab, the founder of the eponymous discount brokerage firm, donated $300,000. James Cox Kennedy, the Atlanta-based chairman of media giant Cox Enterprises, gave $100,000. Schwab is worth a reported $6.4 billion, while Kennedy is worth $10.2 billion — ranking both of them among Forbes’ wealthiest 400 Americans.

The probe also revealed that the two billionaires had a direct stake in a case moving through Montana’s courts at the time of the 2012 election. While neither are residents of Montana, they both own large estates there. The two properties include streams and rivers to which the owners would like to restrict access. But Montana has some of the most liberal laws for recreational waterway use in the country: The state’s 1972 constitution allows broad public access to those waterways.