I've compared 2000 vs 2004 in Florida
http://election.dos.state.fl.us /
Just a basic examination of the numbers:
5 counties FLIPPED from Gore (2000) to Bush (2004)
7 counties Kerry had FEWER votes than Gore (0 for Bush)
63 counties Bush 2004 had HIGHER % of votes than Bush 2000
57 counties Kerry had LOWER % of votes than Gore 2000
In examining the smaller optical scan counties that had higher Dem registration but higher Bush votes (lots of threads on this), only 3 (Hernando, Flagler, Osceola) flipped from Gore 2000 to Bush 2004. So without looking at recent voter registrations, I don't know that we can disregard the Dixiecrat theory (other threads).
19 counties have 22.1% - 34.7% of their population over 65 (2000 Census). These contain 4 of the 5 that flipped (Flagler, Hernando, Pasco, Pinellas). Of these, 2 of the 3 optical scan counties flipped (Flagler, Hernando).
Take from this what you will, but I think it serves as a start to look for discrepancies.
In addition, I've compared the 2000 and 2004 election for Senator (Nelson-McCollum vs Castor-Martinez). While I believe it is more difficult to see anything from this (simply because senators and their appeal are not constant across elections), there are still some interesting anomalies in the numbers.
18 counties FLIPPED from Nelson (2000) to Martinez (2004)
12 counties Castor had FEWER votes than Nelson (0 for Martinez)
54 counties Martinez 2004 had HIGHER % of votes than McCollum 2000
63 counties Castor 2004 had LOWER % of votes than Nelson 2000
In examining the smaller optical scan counties that had higher Dem registration but higher Martinez votes, only 1 (Miami-Dade) flipped from Nelson 2000 to McCollum 2004. Again, without looking at recent voter registrations, I don't know that we can disregard the Dixiecrat theory (other threads).
It does not seem that population over 65 comes into play in the senate race - only 1 county flipped (Citrus), and the 2000 vote was very close.
In addition, 2 counties (Miami-Dade and Orange) had Kerry for president, but Martinez for senate.