The case was before the Public Utilities Commission of Ohio, the Ohio Supreme Court and the United States Supreme Court, and lasted fourteen years.

In 1938 Ohio Governor Martin L. Davey tried to take credit for Austin's appointment, but Duffy asserted his own leadership.

His political path became more difficult: he lost a Democratic primary election for Ohio governor in 1940, general elections for the Ohio Supreme Court in 1944 and 1946, and a party primary for lieutenant governor in 1954.

Duffy wrote a biography of former President William Howard Taft, which was published in 1930.

He was national commander of the American Legion at the Inter-Allied War Veterans' Congress in Brussels, Belgium in 1935.