If Groundwork or Socialist Majority Caucus is the "Sonic" of DSA, then Marxist Unity Group is Shadow. Way cooler and packing heat. Don't be fooled by the ironic blue-and-white color scheme of the caucus, MUG is all reds.
I first became aware of Marxist Unity Group from reading cosmonaut magazine on a bus ride to see my mom in the suburbs. I thought that DSA was a bunch of reformist cowards with fancy professional jobs. Then I heard these guys talking about burning the constitution and instantly became a fan.
Like shadow, Marxist Unity Group's specialty is traumatic flashbacks, not about Maria, but about the world-historic defeat of the left in the failed German revolution of 1918. We need to chart a new course for the revolutionary mass party, while also learning the positive lessons of party-building from the SPD and its splits.