In 2301 we discussed the concept of legitimacy and how the legislative branch -- specifically the House of Representatives -- is designed to lend legitimacy to government. Recent low approval ratings can be attributed partly to the fact that Republicans were in the minority and therefore didn't approve of much of what Democrats were doing in the institution. I suggested that perhaps attitudes would change now that the Republicans are in charge, and that one of the positive consequences of periodic elections is that it allows those not in power to increase their influence, and perhaps their assessments of the institution.
Here's proof, albeit limited, from the Gallup Poll. Republican approval ratings of Congress have increased from 7% to 22% since the election. Still low, but it suggests an obvious connection between elections and attitudes about the institution.