The far left in the USA is not a very cohesive force and virtually lost against the babble of right wing chatter.
The moderate left and right seem to occupy a perilous majority for the time being... but so besieged by the idiocy of the far right that, as you can see in current headlines, the US public is forced to suffer watered-down, compromised action by it's own government as regarding healthcare and other essentials. Most of the US public WANT the government option, WANT socialized medicine... but even many on the moderate left have scrapped that sensible and proven model just because they've been brainwashed into thinking that it could never work here.
There's an ominous sense in the USA among many that collapse is inevitable... gun sales skyrocketed with Obama's election. Americans fear themselves probably more than they fear 'terrorists' from afar. And in that they are correct. We're our own worst enemy.
The difference as I see it is your BNP is like our far right wing, with the difference that OUR far right wing actually has power. And they use it. Prisons overcrowded- Corporate malfeasance on a vast scale (the supposedly left Clinton was even part of that)- projections of power abroad- etc.