You can file suits until the cows come home. It doesn't matter because of "sovereign immunity" (see http://legal-dictionary.thefreedictionary.com/Sovereign+Immu... ).

Basically, the government is immune from lawsuit unless it chooses to allow you to sue it. And this is the presupposition, so they don't need to justify it.

You've got only two defenses against this: (1) The right to vote; and (2) the right to keep and bear arms.