Leading up to 1917 and the declaration of war against Germany, the labor unions, socialists, members of the Old Right, and pacifist groups in the United States publicly opposed participation, the obvious motive for the 1916 Preparedness Day Bombing stemming from this. When Woodrow Wilson ran for reelection in 1916 on the slogan "He Kept Us Out of War", he received support from these groups (although the Socialist Party of America ran its own candidate, Allan Benson). After Wilson was reelected, though, events quickly spiraled into war. The Zimmermann Telegram and resumption of unrestricted submarine warfare by Germany provoked outrage in the U.S., and Congress declared war on April 6. Conscription was introduced shortly thereafter, which the anti-war movement bitterly opposed. Many socialists, typified by Walter Lippmann, became enthusiastic supporters of the war. So too did Samuel Gompers and the great majority of organized labor unions. However, the IWW --"Wobblies"—gained strength by opposing the war.