An administrative law judge has found probable cause that Minnesota Supreme Court candidate Michelle MacDonald violated state campaign law with a claim in a voter's guide that she was endorsed by the state Republican Party.

Judge Jessica Palmer-Denig's ruling, issued Thursday, sends the complaint against MacDonald on to a three-judge panel for further consideration of evidence and possible penalties.

MacDonald is on the ballot Tuesday challenging incumbent Justice Natalie Hudson, who is running for a full six-year term after her appointment by Gov. Mark Dayton in 2015. MacDonald, a West St. Paul private attorney, was an unsuccessful candidate for the state high court in 2014.

MacDonald won the Republican endorsement in that '14 race despite her own legal troubles stemming from a 2013 drunken driving arrest. Her resulting clashes with state party officials has won her numerous critics within the state GOP. At this year's Republican convention, delegates voted to skip Supreme Court endorsements entirely rather than consider MacDonald.

In a submission in October to a Star Tribune voter's guide, MacDonald wrote "GOP's Judicial Selection Committee '16" under the "Endorsements" entry. It was initially posted online but removed a few days later when its accuracy was questioned.

Citing the state's Fair Campaign Practices Act, complainants Barbara Linert and Steve Timmer contended that MacDonald intended to suggest full Republican Party backing. The GOP has had an entity known as the "judicial election committee" that did back MacDonald, but which had no authority to confer full party endorsement.

"It was an honest mistake," MacDonald wrote in an e-mail Saturday to the Star Tribune. She said she was referring to the judicial election committee and not trying to suggest Republican Party endorsement.

Patrick Condon • 651-925-5049