PRINCETON, NJ -- Twenty-one percent of Americans approve of the job Congress is doing, higher than the 13% Gallup measured in September, and the highest rating in any month since May 2011.

The more positive evaluation of Congress could be a delayed reaction to the same factors that brought about improvement in Americans' -- and in particular Democrats' -- views of national conditions in September. Satisfaction with the United States and economic confidence increased significantly in September, mainly because of Democrats' more positive ratings, before leveling off in October. The increases in satisfaction and economic confidence were apparent in the days after the Democratic National Convention at which the party nominated President Barack Obama as its presidential candidate as he seeks a second term in office.

In contrast, congressional approval rose modestly in September -- to 13% from 10% in August -- before this month's more substantial increase.

Supporting the thesis that changes in Democrats' views are driving the improvements in many national indicators, Democrats have shown the greatest increase in their evaluations of Congress this past month, to 30% from 16% approval. Independents' and Republicans' ratings are up more modestly, by eight percentage points (to 20% from 12%) and four points (to 14% from 10%), respectively.

Congress Approval Low for Pre-Election Period

Even with this month's increase, Congress' approval rating is still low from a historical perspective. The average rating in Gallup polls since 1974 is 34%. Congress' current 21% approval rating also ranks among the lowest final pre-election measurements by Gallup in an election year, tied with the 21% reading in 2010 and slightly higher than the 18% in 1992 and 2008.

Historically, lower congressional approval ratings -- typically those below 30% -- have been associated with more turnover of seats by party in Congress, as voters take out their frustrations with the institution by changing its membership. The losses typically occur for the president's party. This relationship holds in both presidential and midterm election years, but is stronger in midterm years. The largest changes in party seats in a presidential election year occurred in 1980 (34 seats when Congress' approval was 25%) and 2008 (23 seats with approval at 18%). There have been larger seat changes in midterm election years, including 1974, 1994, and 2010.

Implications

Americans' evaluations of Congress are still overwhelmingly negative, but not as negative as before. In September, it looked likely that Congress would head into this year's elections with a lower approval rating than at any time since 1974, though things brightened slightly in October.

Nevertheless, Congress' low approval rating makes its members vulnerable to defeat and raises the possibility that the institution's membership could be quite different when the new Congress convenes in January. However, with party control of Congress currently divided, given a majority Republican House of Representatives and majority Democratic Senate -- along with a Democratic president -- it is not clear whether those frustrated with Congress would take disproportionately greater aim at one party's members or another.