I cited as evidence five polls showing incumbent Democratic congressmen trailing Republican challengers. None of those Democrats had scandal problems; all five lost in November.
Today, a lot more Democratic incumbents seem to be trailing Republican challengers in polls. Jim Geraghty of National Review Online has compiled a list of 13 Democratic incumbents trailing in polls released over the last seven weeks.
They're from all over the country: one each from Arizona, Arkansas, Illinois, Mississippi, New Mexico, North Dakota, Ohio, South Dakota; two from Virginia; three from Pennsylvania. Most if not all of these incumbents are personally attractive, hardworking and ethically unsullied.
Some of these poll numbers are mind-boggling. Tom Perriello, a 727-vote winner in Virginia 5 in 2008, has been running two weeks of humorous ads showing what a hard worker he is. A poll shows him trailing Republican state Sen. Robert Hurt 58 percent to 35 percent.
In industrial Ohio 13, which Barack Obama carried 57 to 42, a poll shows incumbent Betty Sutton trailing free-spending Republican Tom Ganley 44 percent to 31 percent.
As Geraghty notes, we haven't seen polls released by many other Democrats on Republican target lists. Most are conducting polls; many have reason to release favorable results if they're available. This looks like a case where the absence of evidence is evidence of absence.
Two years ago, Barack Obama was elected president with a historic 53 percent of the vote -- more than any other Democrat in history except Andrew Jackson, Franklin Roosevelt and Lyndon Johnson.
These metrics -- the generic ballot results and polls in individual districts -- suggest that House Democrats are headed toward historic losses. Quite a swing in 18 months.