Of the 50 U.S. states and Washington D.C., which between them provide the 538 electoral colleges votes for a presidential election, exactly six have been won by the winners of the 1972, 1976, 1980, 1984, 1988, 1992, 1996, 2000 and 2004 elections. It is therefore tempting to argue that the entire 2008 election can be defined by which candidate will win most or all of these states.
Intriguingly, all six have at least one common border with another, and they form a barrier between North and South as well as a barrier between the East and the West. One could walk from the Great Lakes (well, more likely drive) to the Gulf of Mexico without ever leaving one the six.
The furthest to the North is Ohio. No Republican has been elected President without winning that state, and the last Democrat to win a presidential election without winning the Buckeye State was John F. Kennedy in 1960.
Cross the Ohio River and one arrives in Kentucky. Like Ohio, J.F.K. was the last President to be elected without the support of Kentucky voters. However, in most respects this is traditionally a Democratic party stronghold. Since 1956 (General Eisenhower's re-election year), Kentucky has more often been Republican.
Kentucky is generally a lower-taxed state with less industry than Ohio. It also had slavery, whereas the 19th century Underground Railroad for escaped slaves led to Ohio. They should be opposites, but aren't.
Head South from Kentucky and one enters Tennessee. Here the Republicans hardly ever won until 1952 (Dwight W. Eisenhower's first term). However, the voting population nearly doubled in the 1945-1960 period and with it, it seems the Democratic party declined. Most dramatically, in 1968, virtually all the Democratic counties backed George Wallace, the segregationist candidate. The Democrats came third that year, but since then the state has been won by every winner.
Go West (or North-West) from Tennessee and you enter the southern tip of Missouri. This is the mother of all weather vanes. Since 1904, Missouri's electoral college votes have always been on the winning side, except, that same 1956 election where the Democrats took Ohio and lost nationally.
Move southwards again down the Mississippi/Missouri basin and one hits Arkansas, where Bill Clinton was Governor. Like Tennessee, Arkansas was solidly Democrat (never voted Republican from 1872 to 1972) and the segregationist candidate in 1968 won there. However, only a southern Democrat (Bill Clinton or Georgia's Jimmy Carter) has beaten a Republican since Richard Nixon in 1972.
Finally, push downriver to Louisiana. This is again a traditional Democratic state. Although Eisenhower managed to win there in 1956 and Louisiana managed to back segregationist candidates TWICE since 1945 (in 1948 and 1968), this was another state where Democrats used to win well over 80% of the vote on occasion.
In 2004, John Kerry came close in Ohio, but nowhere near winning any of the other states. I reckon that one difference this time round is that areas not considered vulnerable to either side in the past two elections, for example, Connecticut and Maryland or Indiana and Kansas.
Kansas of course was unique in having a Republican majority in every one of the state's counties. Not this time, if Barack Obama is the candidate...
Michael Barone at RealClearPolitics, says it's time to throw out the maps. Or maybe dig out some old ones.