The National Endowment for the Humanities, with a RICO suit. Causation: that the NEH, a government body, is attempting to insert itself into political affairs with taxpayer monies; that those taxpayer monies are being disbursed to persons engaged in fraudulent activities; and that the intent of said disbursment is to undermine constitutionally protected civil liberties.
It's called "conspiracy to deny civil rights under color of authority."
I can certainly see that kind of a lawsuit providing information and decisions regarding the NEH's authority to engage in such activities, but I don't think that such a lawsuit would produce much relevant information concerning the importance of the right to bear arms.