I think that people tend to expect the impossible out of political leaders. We want them to know what they're doing but not be "part of the Washington establishment". We want them to take stands on particular issues, but if they really think about their stance and end up modifying it, then they're waffling. We want them to attack the other guy, but still seem respectable. They shouldn't be influenced by special interests, unless it's our special interests (NRA, etc) in which case it's perfectly fine.
We want our Congressional leaders to listen to their constituents, but they should not miss votes in Washington, but they should not stay in Washington too long, but they should not lounge around at home.
There seems to be a lot of paradoxes here...we're saying, "No, do this!" "No, do that!" "No, do both of these at the same time and then five more things!"
What human can possibly live up to these crazy standards? Certainly they need to get things done efficiently and without being corrupt, but a lot of the expectations that we put on them are extraneous to doing the actual job. We need to recognize that these are mortal individuals that we elect to work within a much larger system which demands compromise at every level. It's like marriage - if you get someone who you somewhat agree with, consider yourself lucky.