If you're referring to Lincoln vs. Thaddeus Stevens on slavery, then I'd respond that things may have turned much better, particularly for Americans of African descent, if Stevens had got his way.
I do appreciate the strategic thinking behind your suggestion that Snowden or Greenwald may eventually reveal what they are obliquely referring to. My personal opinion is that Greenwald led with his strongest story -- I don't think they have much more. But I have nothing to back that up. But clearly Wyden and Udall have a whole lot more.
In the end, I'm the type of person who believes that their oath to the constitution supercedes any strategic concerns.