The US right is as much of a terrorist threat as are Muslims

First off, there is nothing in the Constitution which allows for a "right" to rebellion.  If Anything, the Constitution is very clear that it prohibits waging war on the US (Article III, Section iii).

Unfortunately, I do not hear many people calling bullshit when people say it is their "right" to own a gun to fight the evil government.

But ponder this:

Let's not forget Timothy McVeigh:

Or Anders Breivik:

Maybe we need to worry about white guys as much as Muslims.