If the state is illegitimate then it is permissible or perhaps an obligation to topple it, according to people like the revolutionaries that founded the USA. That is, it doesn't necessarily matter what is legal or not, if the state misbehaves then you should put it to the guillotine or fire or bear arms or whatever suits you.

As an outsider it's always funny to see people write about the "American Left", as if there were any leftist movements of national importance in the US. As if Food Not Bombs had at some point had a majority in congress or something, it's just a ridiculous idea. If that happened there would be a bloody purge, Pinochet style but bigger.