Rubuta ci gaba ga wannan sakin layi - Erickson ya kasance Richland County District Attorney daga 1936 zuwa 1938 kuma ya kasance Mataimakin Alkalin Kotun Montana daga 1939 zuwa 1945. Ya kasance wakili ne a Babban Taron Kasa na Demokradiyya a 1948, 1952, da 1956
Ka yi haƙuri. A shekara ta 1944, ya yi takarar Gwamnan Montana, ya lashe zaben fidda gwani na jam'iyyar Democrat kuma ya ci gaba zuwa babban zaben, inda ya yi adawa da Gwamnan Republican Sam C. Ford. Ford ya ƙare da kayar da Erickson ta hanyar babban bambanci don lashe wa'adinsa na biyu a matsayin gwamna. Erickson ya kalubalanci Sanata Burton K. Wheeler a cikin Jam'iyyar Democrat na farko a 1946, kuma ko da yake ya ƙare da kayar da Wheeler a cikin damuwa, ya rasa babban zaben zuwa Sanata na Republican Zales Ecton. Ya sake tsayawa takarar gwamna a 1948, amma ya gama na uku a zaben fidda gwani na jam'iyyar Democrat a bayan tsohon Babban Lauyan Montana John W. Bonner da Arthur Lamey. Daga 1956 zuwa 1958 ya kasance shugaban Jam'iyyar Democrat na Montana kuma daga 1962 zuwa 1973 ya kasance memba na Kwamitin Kasa na Democrat.