 Mertz akatanga kusarudzwa kuDare reParamende muna 1948 nokuda kweDunhu rechi16 reMilwaukee, achibatira kubva muna 1949 kusvika muna 1957. Akamirira 9th Milwaukee district kubva muna 1963 kusvika muna 1965. Mukuwedzera, akanga ari nhume ku1952 Democratic National Convention. Mertz akafa muna May 1970. 