But catz...
I already thanked (and tried to rep) your OP.
And now you seem hell bent on convincing me I
should be worried about the NBPP.
Should the NBPP be investigated and prosecuted?
Absolutely, the leadership and most participants are thugs.
I don't know how this will be charged, but I suspect terroristic threats at the low end, and at the top end, RICO, depending on how far the conspiracy to actually commit a crime goes within the organization. As a result of making this threat, their status as an organization (administratively) will probably also be compromised.
Should Americans be cowering in their homes because of the terrifying NBPP?
Absolutely not. As a whole, racist groups (of any hue) aren't very well organized, they're typically run by felons and/or criminals (who aren't very good at their criminal activities or they wouldn't have been arrested/convicted), they're typically more about soundbytes than they are direct action, and they don't have very much support from the communities that they claim to represent.
I know, nuanced positions like this are so hard to fit into a partisan soundbyte...