America With Proportional Representation

[Peter the Lefty]

I think it might be likelier for this civil rights party to merge into Labour.  But yeah, I could see a fusion of the Socialists and the La Follette Progressives merging into one "Labour" Party, while Wilsonite Democrats and Charles Evans Hughes Republicans (and probably a lot of TR's former supporters as well) form a mildly progressive center-to-center-left party or bloc.  The Republicans would become your equivalent of most Anglophone center-right Tory parties.  Southern Dixiecrats would end up forming their own party.  I could also see a Civil Rights Party becoming big initially, but I'd imagine it would merge with Labour not after too long.  Eventually a Libertarian Party might emerge, and eventually a Green Party as well.