Radical reconstruction was successful. Kulturekampf is flipped, with a traditionalist Prussia cracking down on secularists and causing more emigration to America. Nobody throws dynamite in Chicago. Socialists support WW1. De Leon stays more relevant than Debs, which leads to more structured control of labor. The lefties remain antiwar but not from a overtly antiimperialist position, but rather focus on poor conditions and needless casualties. Bonus marches arent totally concentrated in Washington, they're still violently dispersed but there is an exchange of gunfire that leads to rioting.
Meanwhile the whites form an alliance with the greens and left Bolsheviks unwilling to let loss of territory to Germany go. Republican France is even more revanchist and starts purging the traditionalists supported by alt Prussia, which scares Britain and leads to it looking for a new ally.