In the 1940s, he was active in the state of Washington as a leader of the Democratic and Progressive parties, and was a backer of Henry A. Wallace in the 1948 presidential election.

He built a reputation as a capable criminal defense attorney, and practiced until his sudden death from a heart attack in 1956.

[4] O'Connell's friend Robert Marshall was the chief of forestry in the Bureau of Indian Affairs from 1933 to 1937, and head of recreation management for the United States Forest Service from 1937 to 1939.

[4] Bernard was a communist sympathizer, and O'Connell and Bernard were in Spain to demonstrate support for the Abraham Lincoln Brigade, one of the International Brigades organized by the Communist International to oppose the fascists led by Francisco Franco during the Spanish Civil War.

[4] The bill would have required all members of the Communist Party of the United States to register with the U.S. Attorney General, but opponents were successful at preventing its passage.

[9] In June 1949, he signed a letter in support of the defendants in the Smith Act trials of Communist Party leaders.

[11] In 1950, the House Un-American Activities Committee (HUAC) singled out O'Connell as an alleged communist sympathizer in his role as chairman of the National Committee to Defeat the Mundt Bill (NCDMB), the sponsors of which, Representatives Karl E. Mundt and Richard M. Nixon, had both been HUAC members.

[12] In 1955, he appeared before HUAC, which questioned him widely about possible communist ties, including his support of Henry A. Wallace's bid for president as a Progressive in 1948.

[13] O'Connell denied any affiliation with communists or communism,[14] making use of his debating skills and training as an attorney to effectively counter the evidence presented against him.

For instance, when asked whether he held any position in the organization, O'Connell at first said, "No," but then agreed that he had joined NCDMB in June 1948 and specified "probably September 13," 1950, as the end date for this affiliation.

[20] After the death of her husband, she worked in retail sales and management, and later owned and operated several Great Falls businesses, including bridal and formal wear stores.