I did this quick study right after the Census shift in 2000.

This represents how the electoral vote in 2000 would have differed if you applied the 2000 census that most closely represented the population at the time.

Bush -
Ariz., Texas, Florida, Georgia; + 2 each for Bush = +8
Nevada, Colorado, North Carolina; + 1 each for Bush = +3
Oklahoma, Indiana, Ohio, Miss; -1 each for Bush = -4
--------------------------------------------------------------------
Net gain for Bush = 7 electors.

Gore
Calif.; +1 for Gore = +1
Wis., Mich., Ill., Conn.; -1 each for Gore = -4
NY, Penn.; -2 each for Gore = -4
--------------------------------------------------------------------
Net loss for Gore = -7 electors.

This basically gave Bush a 14 point head-start in the last election and I think the trend will continue. The next census won't make any real difference to us until the 2012 presidential election but with the trend the way it is southern states Republicans should pick up many more electors if the states are not diluted to the extent that they swing Democrat.