About one in five U.S. registered voters (21%) say most members of Congress deserve re-election, the lowest percentage Gallup has found in the 20-year history of asking this question. The prior lows of 28% were recorded in 2010 and earlier this year.
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Voters are more charitable in their evaluations of their own member of Congress, with 54% saying he or she deserves re-election, compared with 57% in May. The electorate has consistently been more likely to say their member of Congress deserves re-election than to say most members do. However, even though a majority believes their own representative should be re-elected, the current percentage is on the low end of what Gallup has measured historically. The lowest readings were 48% in October 1992 and 49% on two occasions in 2010.
So did a lot of incumbents lose?  No.
In the Senate, 10 incumbents retired this year, leaving 23 who sought reelection.  One (Lugar of Indiana) lost a primary and one (Scott Brown of Massachusetts) lost the general.  The remaining 21 all won, for a reelection rate of 91 percent.  That is on the high side for Senate elections.  
- 25 retired,
 - 14 sought other office,
 - and 5 resigned or died without replacement before the election.
 
- 13 lost primaries,
 - 24 lost the general election,
 - 2 are running behind in undecided races, and
 - 1 is certain to lose an incumbent-v.-incumbent runoff in Louisiana, so
 - 351 won reelection.
 
And even that figure gives an inflated sense of anti-incumbent sentiment.  Of those who lost, a number were running in substantially new territory because of redistricting (e.g., Mary Bono Mack of California).