Pedzisa mutsara unotevera: Erickson akanga ari Richland County District Attorney kubva muna 1936 kusvika muna 1938 uye akanga ari Associate Justice weMontana Supreme Court kubva muna 1939 kusvika muna 1945. Akanga ari nhume kuDemocratic National Conventions muna 1948, 1952, uye
Muna 1956. Muna 1944, akamhanya kuti ave Gavhuna weMontana, achikunda musarudzo yeDemocratic uye achienderera mberi nesarudzo huru, kwaakashora Republican incumbent Gov. Sam C. Ford. Ford akapedzisira akunda Erickson nechiverengero chakakura kuti akunde nguva yake yechipiri segweta. Erickson akapikisa Sen. Burton K. Wheeler muDemocratic primary muna 1946, uye kunyange zvazvo akapedzisira akunda Wheeler mukushatirwa, akarasikirwa nesarudzo huru kuRepublican State Senator Zales Ecton. Akamhanyira gavhuna zvakare muna 1948, asi akapedza wechitatu muDemocratic primary shure kweaimbova Montana Attorney General John W. Bonner naArthur Lamey. Kubva muna 1956 kusvika muna 1958 aive sachigaro weDemocratic Party yeMontana uye kubva muna 1962 kusvika muna 1973 aive nhengo yeDemocratic National Committee.