So it's remarkable, especially in this venomously anti-incumbent environment, that four of the House's most precarious incumbents want to come back to Washington ASAP.
"Up through late May and early June, through WorldCom, I was arguing that we were looking at the most pro-incumbent environment that I've seen in a 22-year career," said Bill McInturff, a Republican pollster who has conducted regular national polls of the electorate this year.
The Liberals flooded the east coast in what has been dubbed a "crimson tide," taking out opposition candidates including strong NDP incumbent and environment critic Megan Leslie in Halifax.
The ads helped spark a modest improvement in his public approval, but the governor remains a broadly unpopular figure with a paltry amount of money for an incumbent, in an environment in which Democratic incumbents are widely seen as at risk.
The school's sustainable finance programme said overcapacity, combined with global moves to cut carbon emissions and the shift towards more cost-effective renewables, could leave the country with a stranded investment in coal plants worth $56bn "The expansion of coal in Japan appears to be predicated on a benign environment for incumbent utilities," the programme's director, Ben Caldecott, said.
That's when potential challengers and incumbents read the national environment and decide to run or not.
"We're weathering the greatest economic downturn since the Great Depression," said David Axelrod, a senior adviser to Mr. Obama, "so it's not a hospitable environment for incumbents generally.
Mr. Wolfson disputed the idea that Mr. Bloomberg performed poorly at the polls, citing a tough political environment for incumbents around the New York region; Gov. Jon S. Corzine of New Jersey, for example, lost his job.
And few areas of the country have been as hard-hit by the recession as the Midwest, creating an environment where incumbents — in this case, Democrats — faced a decidedly rough road to re-election.
Quinn is grappling with a state budget crisis of record-breaking proportions, and a difficult electoral environment for incumbents generally and for Democratic ones in particular.
We had this race rated as "lean Democratic" in February on the basis of reasonably strong approval ratings for Mark Pryor, the Democratic incumbent, despite an otherwise difficult environment in the state.
