While Congress' approval rating is below 20%, individual members ratings are generally a bit above 50%. The explanation is simple. To be a member of Congress the individual must get over 50% of the vote, and most congressional districts lean either to the right or the left. When it comes to doing anything, to a great extent the left and right members cancel one another out with the side with the higher percentage getting their way. But, those that voted in a member in the minority generally disagree with what the majority did, while those that support the majority position don't thing it went far enough. Low overall ratings of Congress are to be expected regardless of which party holds the majority.