One political cause of the Great Depression was the Smoot-Hawley Tariff Act of 1930. This act was passed by the United States government and imposed high tariffs on imported goods, aiming to protect domestic industries. However, it led to retaliatory tariffs from other countries, reducing international trade and worsening the global economic situation. The increase in trade barriers contributed to the spread of economic decline and intensified the worldwide economic crisis during the 1930s.