Martin Dies Jr. holds a Bachelor of Laws degree from the National University School of Law. He practiced law in Texas and served as a district judge. Dies Jr. transitioned from the private sector to a political career, elected to the House of Representatives from Texas. He chaired the Special Committee to Investigate Un-American Activities, reflecting his focus on national security and loyalty issues.

Martin Dies Jr. initially supported the New Deal but later opposed it due to labor unions' growing influence, revealing a complex stance on economic intervention. His belief that "the large alien population is the basic cause of unemployment" showcases a rigid nativist perspective. As chairman of the Special Committee to Investigate Un-American Activities, Dies Jr. exhibited a highly localized approach to national security, targeting perceived internal threats with a fervent intensity.