Numerous other Democrats are still considering getting in.
Flynn appeared with a number of Democratic gubernatorial hopefuls at a forum Monday in Milwaukee. He planned stops to talk about his candidacy on Tuesday in Glendale and Madison.
The 70-year-old Flynn is a retired partner with the Quarles and Brady law firm. He previously ran unsuccessfully for U.S. Senate in 1986 and 1988 and for the U.S. House of Representatives in 1978 and 2004.