Obviously, though, that's not actually how it works. We disapprove of Congress, but we re-elect our own Senators and Representatives. That's because most of us do not see them as the problem. My Congressmen are fine, and doing well; it's your Congressman who need to be replaced, so why are you not doing something about that?
There are only two possible answers to that. Either you are pleased with your representation and your dissatisfaction is with the other members of Congress, or you are in the minority in your district, in which most of your neighbors are content with your representation.
That is to some degree an oversimplification. After all, incumbency is a major advantage--the incumbent already has some degree of name recognition, and that in itself gives him an advantage not only at the polls (many will vote for the name they recognize) but also in the fundraising (more people support politicians they already know). There is also a political advantage. Because of the way the legislature functions internally, if the Senator from your state or Representative from your district has been there for multiple terms he is more likely to wield power, as having his choice of committees, chairmanships, and leadership positions. If John Boehner or Nancy Pelosi were replaced, their replacements would be freshman and the people they represent would have considerably less power in government.
Yet it is also the case that the polarization in government of which we spoke is also found among the voters. Democrats are unhappy with Congress because it is their perception that Republicans are impeding the progress that might be made if they could be replaced by Democrats; even if their own Democratic representatives are less than what they hoped it is certainly better to send them back than to increase the Republican presence. Republicans, similarly, are unhappy with Congress because of the direction Democrats are taking the country. Certainly members of both parties would complain that the problem is "gridlock", but the solution to gridlock depends on which direction you want the country to move. What we disapprove about Congress is either that our neighbors are sending the wrong people to do the wrong things, or that everyone else in the country wants something different from what we want.
Ultimately, then, the disapproval of Congress is simply a reflection of our disagreements with each other, of the polarization happening in these United States, the failure of mutual understanding that led one Hollywood actress to suggest carpet bombing the largely Republican states in the middle of the continent and which drives calls for impeachment of the President for everything from doubts about his citizenship to his use of executive directives. We are not going to be happy with our government until we can listen to each other, understand each other, and come to some sense of respect for our diverse opinions--and perhaps a more unified vision of a direction for the future of this land.
I do not see that happening any time soon.
