DON'T EVEN NEED MUCH SNAP TO GET BACK:

Can Republicans Count on a House Snapback? (Stuart Rothenberg, 2/05/07, Real Clear Politics)

The history of recent surges and snapbacks is pretty clear. In 1964, during the Democrats' anti-Goldwater surge, Democrats knocked off 39 GOP incumbents and won eight Republican open seats. Two years later, the Republicans snapped back, defeating 39 Democratic incumbents.

The wave that accompanied Ronald Reagan's presidential victory in 1980, which ousted 27 Democratic officeholders and secured 10 Democratic open seats for the GOP, beget 1982, when 22 GOP incumbents were bounced from office. And the wave against President Bill Clinton in 1994, which took down 34 Democratic House Members and turned a stunning 22 Democratic open seats red, produced 1996, when 18 GOP incumbents lost bids for re-election. [...]

In November, Democrats knocked off 22 GOP incumbents and added eight Republican open seats. That means that the number of Republican incumbents defeated in their bids for re-election in 2006, while substantial, was below (and in some cases well below) the number of incumbents defeated in earlier waves.