 Dockweiler was defeated in the August 31, 1926 Democratic primary for the U.S. Senate nomination for California, losing to John B. Elliott.Elliott was the contestant sponsored by the then former U.S. Treasury Secretary William Gibbs McAdoo.Dockweiler served thrice as a delegate to the Democratic National Conventions of 1908 (Denver), 1936 (Philadelphia), and 1940 (Chicago).