It's gonna take a hell of a lot more than just overthrowing the DNC leadership for progressives to regain & extend power, because, as what happened in Nevada when Sanders Democrats briefly took over the Nevada Democratic Party apparatus, the ConservaDem faction can merely sit on their hands, wait patiently for Republicans to come in & blow out the progressives, and then merrily return to their seats of power as if nothing happened.
Indy Left is the only real solution.