Karl Rove takes us on a fascinating tour the four key states he believes are essential to the 2008 election: Colorado, Virginia, Michigan and Ohio. His bottom line: “Mr. Obama must carry Colorado or Virginia and add another small state to his column. If Mr. McCain carries Michigan as well as Ohio, it would make Mr. Obama’s Electoral College math very difficult.”

Rove’s analysis should put much of partisan punditry into proper perspective. First, national polls are fun but largely irrelevant. Remember Hillary Clinton and Rudy Giuliani’s double-digit leads months before the first votes were cast?

Second, we might get a better sense of the race if we seriously consider the voters in these particular states. Are Michigan voters going to be impressed by a Berlin rally or will they roll their eyes in disgust? Does Barack Obama’s record on the Seond Amendment mean more than his rhetorical appeal for “change”? Will recent events in Georgia and the success of the surge give John McCain extra help where he needs it most–among Colorado and Virginia military families, for example? And do voters in any of these states like Obama’s race card gambit? In short, when one starts thinking about actual voters, in specific states, it gives one a newfound appreciation for what matters and what doesn’t.

And one thing stands out: there are a lot of older voters in all four of these states. Perhaps age really does matter.

Finally, if we look at current polling in these states we can see how terribly tight a race it is. Virginia and Ohio are virtually tied. Colorado shows less than a two-point lead for Obama. Obama is up by an average of three, still within the margin of error, in Michigan.

I’m inclined to follow Rove’s advice and keep an eye on those states and evaluate much of what goes on in the race in light of the importance of these hot spots. As weak a candidate and as thin a record as he might have, Tim Kaine might hold the key to Virginia. So he’s likely the prohibitive favorite for VP. Michigan’s calamitous Democratic reign may have more to do with the outcome in 2008 than any other factor. And so it goes if you remember that the only number that matters is 270.