First the federalists (socdems) and the nationalists (radsocs), a very interesting move since people tend to forget that you got left wing nationalism too
The only thing I miss is a hint of christian socialism, Norman Thomas was a christsoc and a member of my church (presbyterian)
Then we got the syndies, like on Huey Long tree, you got options to take to better configurate the nation as you want, this is awesome
Now to the cherry of the cake
Earl Browder was the leader of the USA communist party, but he didn't followed marxism leninsm, he had his own communist toughs and theories based on the american patriotism, he was a patriotic communist, to the point he was denounced as a traitor by the soviets and re-replaced with Foster (whom he had replaced in 1932)
Thus, Browder can have his Marxist Browderist dictatorship, while Foster goes Mar-lenin to the brink reviving the whole 1920s in the USSR
Their military tree
And the CSA foreign policy