The paradox of compromise is that politicians who know exactly where they want to go can find the give-and-take of legislating much easier than do those who either test ideas against the polls (public opinion is not static) or those who don’t have any large objectives. You can’t know how to move two steps forward and one step back if you aren’t sure of the direction in which you are walking. You cannot know the difference between a minor concession and a major betrayal of principle unless you know what your principles are.

–E. J. Dionne