In 1942, he enlisted as a private in the United States Army with combat service in the European Theater of Operations with the US 28th Infantry Division.

After the war, he was engaged as a vocational rehabilitation representative for the Retraining and Reemployment Administration with the United States Labor Department until his resignation in 1947.

Potter was elected on August 26, 1947, as a Republican to the United States House of Representatives from Michigan's 11th congressional district for the 80th Congress to fill the vacancy caused by the death of Fred Bradley.

He was elected to the United States Senate in 1952 to fill the vacancy caused by the death of Arthur H. Vandenberg, replacing Blair Moody, who had been appointed to the post.

In his 1965 memoir, Days of Shame, he outlined the battle between moderate Republicans and Democrats to contend with Sen. Joseph R. McCarthy.