At least $1.6 million was spent on the Montana Supreme Court race between Justice Mike Wheat and challenger Lawrence VanDyke this year, records show, likely making it the most expensive judicial race in state history.

The vast majority of that money — at least $1.36 million — came from groups other than the candidates, such as Montanans for Liberty and Justice, which was financed largely by plaintiffs’ attorneys and organized labor, and the business-backed Republican State Leadership Committee.

Wheat won his second term on the seven-member court, defeating VanDyke with 59 percent of the vote.

Several conservative and pro-business groups lined up behind VanDyke in the nonpartisan race, producing ads and mailers promoting VanDyke and attacking Wheat as a “liberal” justice with a partisan agenda.

The only group supporting Wheat was Montanans for Liberty and Justice, but it spent nearly $640,000 on the race, or about half of the outside money reported publicly.

Wheat said Wednesday he thought the contest might attract some outside money, but had no idea it would turn out to be so much.

Wheat, a former state senator from Bozeman who practiced law for 28 years before being appointed to the Supreme Court in 2010, said he thinks this level of “uncontrolled spending” is not good for judicial races in Montana or anywhere.

He said it may discourage good, qualified people from running for the state Supreme Court.

“Why would a person want to give up their legal career to go out and campaign, because now you’re going to have to go out and campaign for a long time, to counter the money, and it’s going to get ugly, and it’s going to get dirty,” he said. “Why would people want to do that?”

VanDyke also said during the race he thought outside money might be a factor, and that he knew he probably couldn’t win without some outside help, because he wasn’t an incumbent or particularly well-known.

VanDyke grew up in Montana but worked as lawyer primarily in Washington, D.C., and Texas, before he was appointed state solicitor under Republican Attorney General Tim Fox in January 2013. He left that job in the spring.

Spending on the race included:

v The $637,000 by Montanans for Liberty and Justice, which got $365,000 from the Montana Trial Lawyers Association. Other contributors to the group included labor unions, individual lawyers and the campaign of U.S. Sen. John Walsh, D-Mont.

The group produced TV ads and mailers supporting Wheat and attacking VanDyke as being “in the pocket” of corporate interests

v The Republican State Leadership Committee, which is funded primarily by corporate money, spent $477,500 on VanDyke’s behalf, on media ads and mailers. Montana was one of only two states where the Washington, D.C.-based group spent money trying to influence a top judicial race.

v Americans for Prosperity-Montana spent about $180,000 on a pair of TV ads attacking Wheat. The pro-business group is not required to report its spending, but spoke publicly about its efforts.

v Montanans for a Fair Judiciary, a group supported by business interests, reported spending $60,000 in support of VanDyke.

v The candidates themselves collectively raised and spent about $250,000 on their campaigns. Supreme Court candidates in Montana can accept individual contributions of up to $320.

An anti-abortion group, Women Speak Out PAC, also spent money on a mailer attacking Wheat, but did not report its spending to the state Political Practices Office.

Montana’s other Supreme Court race, between Justice Jim Rice and challenger W. David Herbert, didn’t attract any outside money. Rice easily won re-election with 78 percent of the vote.