A report by supporters of campaign finance reform says special interest groups spent 6.7 million dollars on state legislative races last year.
The Wisconsin Democracy Campaign says special interests spent 4.3 million dollars on issue advertising and 2.4 million dollars on ads that were for or against candidates.
The report says the state's largest teachers union spent nearly two million dollars backing Democratic candidates or tearing down Republican ones.
That includes 569-thousand dollars spent by the Wisconsin Education Association Council spent in support of Democratic Senator Robert Wirch.
Wirch defeated his Republican challenger.