During every Open Seat Presidential elections. The Presidential Nominee of the of the Party out of Power carried all of the State the Party's Presidential Nominee of the last Presidential Election carried.
In 1984- Walter Mondale(D)carried only MN and DC.
In 1988- MN and DC went for Michael Dukakis(D).
In 1996- Bob Dole(R) carried AL,AK,CO,GA,ID,IN,KS,MS,MT,NE,NC,ND,OK,SC,SD,TX,
UT,VA,and WY.
In 2000- All of the States Dole carried in 1996 went for Bush.
2004- John Kerry(D) carried CA,CT,DE,HI,IL,ME,MD,MA,MI,MN,NH,NJ,NY,OR,PA,RI,
VT,WA,WI,and DC.
The 2008 Democratic Presidential Nominee will carry all of the States Kerry won in 2004.
Secondly In 1992- Bill Clinton won Colorado,Georgia,and Montana. But lost Arizona and Florida. In 1996- Bill Clinton won Arizona and Florida, but lost Colorado,Georgia,and Montana.
In 2000 Al Gore lost Arizona,Colorado,Florida,Georgia,and Montana.
George Bush won NH in 2000 but lost IA and NM.
In 2004- Bush lost NH but won IA and NM.
The 2008 Republican Nominee is likely to lose Iowa,New Hampshire and New Mexico.

The 2008 Democratic Presidential Nominee's electoral vote Base is at 264.

States that Clinton carried in 1992 and 1996 but went for Bush in 2000.
Arkansas
Kentucky
Louisiana
Missouri
Nevada
New Hampshire
Ohio
Tennessee
West Virginia
All of those states except West Virginia voted for Bush Sr. in 1988.
excluding Iowa and New Mexico. The 9 Red States likely to turn blue in 2008 are
1)Ohio
2)Nevada
3)Colorado
4)Florida
5)Missouri
6)Arkansas
7)Arizona
8)West Virginia
9)Virginia

Who ever can win one or two of those states can win the 2008 Presidential Election.