On November 2, 2010, Wisconsin Green Party Assembly nominee Ben Manski received 31.11% of the vote, in a race with Democratic, Republican, and Constitution Party nominees as well. Manski placed second, well ahead of the Republican nominee, in the 77th district, centered in Madison.
That was the first time a minor party nominee for Wisconsin legislature had defeated one major party opponent since 1944, and also the first time since 1944 that a minor party legislative nominee in that state had exceeded 30% of the vote. Manski is Executive Director of Liberty Tree. He won the endorsement of the state’s long-serving Democratic Secretary of State, Doug La Follette. He was also endorsed by two Democrats who ran for that seat in the 2010 primary, by several unions, and by many local elected officials. Here is his campaign web page.
In 1944, the Progressive Party (a party that existed only in Wisconsin) had elected six Assembly members and a State Senator. In 1946 the Progressive Party disbanded and its leaders became Republicans.
Wisconsin is another state that uses a straight-ticket device, which always injures minor party candidates, especially when they are running for an office not near the top of the ballot. Manski calculates that he won more popular votes than any other candidate, among voters who did not use the straight-ticket device. There were no other Green Party nominees on the ballot in Wisconsin in 2010.