Secession by any part of the United States would be unequivocally a good thing. All in-fighting and division in the imperial core is good insofar as it weakens the empire. No matter by who or how it happens.
Whether it is realistic is another question. At the moment the material conditions are probably not there yet and any overt involvement with secessionist activities on the part of socialists would be tactically unwise.
Secessionism would give the government an easy excuse to declare your group criminal and imprison you. Let the right wing be the ones who push for it. They get much more leeway from the state for this sort of thing.