Isaacson & Walsh, P.C., is incorporated in Arizona as a professional corporation.  The firm represents a broad range of clients before the Arizona Legislature and Arizona state government.  Don Isaacson founded the lobbying practice in 1985 and is the shareholder and the director of Isaacson & Walsh.  Don previously served as Rules Counsel, Majority Counsel and Director of Research for the Arizona House of Representatives.    


The firm employs two other professionals. Cheyenne Walsh, an attorney, joined the firm in 2015, and has ten years of experience representing clients before the Arizona Legislature and an additional three years working on the Arizona legislative staff.  Marie Isaacson joined the firm in 2018 and has thirty years of experience in Arizona state government.  Most recently, Marie served as the Director of Human Resources and the Director of Benefits for the State of Arizona.  


The firm of Isaacson & Walsh, P.C. was first formed in 1975 as Ladendorff & Ridge, P.C.   Don Isaacson joined the firm in 1980 as a young associate, followed two years later by Steve Duffy.    In 1983, when G. Henry Ladendorff retired from the practice of law, Don Isaacson joined Warren C. Ridge as a shareholder and the firm was renamed Ridge & Isaacson, P.C.  The firm moved its offices to what is now the CBIZ Plaza in Phoenix, where it remains today.  Steve Duffy became a shareholder in 1987.  Upon the retirement of Warren Ridge in 2003, the firm’s name was changed to Isaacson & Duffy, P.C.  and continued as such until the end of 2009, when Steve Duffy retired from the firm.  Norm Moore joined the firm on January 1, 2010 and left on December 31, 2014.  During this time period, the firm operated as Isaacson & Moore, P.C.  When Cheyenne Walsh joined the firm in January  2015, the firm became Isaacson & Walsh, P.C.