On the other hand, why wouldn't they try to protect themselves by trying to defund the NSA programs by proposing a new bill? There's public outrage which they can use for their own benefit and they could easily frame this as defending the American citizens while covering their own asses, but they're not doing that either. In fact, the amendment that was proposed to defund the NSA phone surveillance didn't pass, so what's going on?

Also, blackmail isn't that easy. If something embarrassing is revealed about a politician who seemed to be critical of the NSA, you think people wouldn't start pointing fingers to the NSA and accusing them of blackmail?