Right, and this factor helped give the GOP a 52 seat gain, and obviously the Dems, for this reason as well as gerrymandering, can't possibly gain 52 seats.
However, everything is in relative terms. An equivalent to 1994 in terms of the political climate would mean a Democratic gain of 18-24 seats. This calculation is already taking into consideration the overall political landscape factors that you mentioned. So my quetsiton is why the Democrats won't even gain 18-24 then given Bush's current situation.
At least, this is assuming I understand Sam's 18-24 figure accurately; I assume he is saying that if the political factors (not the demographic or geographical factors) are as bad for Republicans this year as they were for Dems in 1994, then this would be an equivalent result.
So while a Democratic gain of 20 seats wouldn't look like much in historical terms, it would be as impressive as the GOP's 52 seat pickup in 1994 in terms of the difficulty of the accomplishment.
That is correct.
Also aiding my judgment is that there are only 22 Republican seats, which, against the Bush 2000/2004 adjusted mean voted under 50% Bush. Only three of those seats are open in 2004. These are the meaty targets in "wave elections" and you should recognize which ones they are in the above lists.
As I recall, nearly 50-60 seats fit that category in 1994, using a 1992/1996 adjusted mean Clinton vote.
In addition, there were a number more open seats in that election also. The GOP won 22 open seats and knocked off 34 incumbents. The Dems won 4 seats, all of which were Dem +5 against the mean that year.