The figure was released Wednesday by the Brennan Center for Justice at New York University’s law school. It says most of the money came from outside groups.
The race is between incumbent Justice David Prosser, who’s generally considered conservative, and challenger JoAnne Kloppenburg, who’s seen as more liberal.
According to the Brennan Center, the liberal Greater Wisconsin Committee has spent about $769,000 in the last two weeks on ads attacking Prosser.
The biggest spenders on the other side are Wisconsin Club for Growth and an arm of Wisconsin Manufacturer & Commerce. The conservative groups have combined to spend about $648,000 against Kloppenburg.
Those numbers are expected to increase dramatically heading into Tuesday’s election.