As the conventional wisdom of six months ago (Clinton versus Giuliani) looks increasingly wrong on both sides, it's worth looking at another potential matchup of national "front runners." Of course, an Obama versus McCain matchup may look just as unrealistic by mid-February, but here's a likely scenario.
The national poll matchups present a mixed picture and most haven't been updated in the last month, or so. But there seems no question that absent a major flareup in Iraq, McCain is the best candidate the GOP can come up with. So let's assume an Obama versus McCain scenario.
From the "generic" matchups it seems reasonable to assume that the Democratic candidate can count on, say, 35% of the vote regardless of the nominee. The GOP's "brand" problem puts them at about 30%. That leaves about 35% of the electorate up for grabs.
If those assumptions are correct, it means that the GOP candidate will have to carry about 58% of the "independents" to surpass 50% of the popular vote. It's not unreasonable to assume that McCain might carry a majority of independents, but a 58-42 split is a landslide. That seems very unlikely,especially since independents currently say they'd prefer a Democrat over a Republican President by nearly a 60/40 margin. Assuming that Obama's apparent appeal to independents holds, a McCain landslide among those voters looks even less likely.
Of course, as we all know, a popular vote win can be meaningless. But that's true only within some fairly narrow parameters. It's very, very unlikely that a candidate could win more than 51% of the popular vote and still lose the election in the electoral college.
So, how does the electoral college look? If one assumes that the Democrats will carry the entire Northeast, Mid-Atlantic, upper Midwest, and West Coast, their total electoral vote is 259. (That assumes, of course, that California doesn't allocate their votes proportionately, but that seems a relatively safe assumption.)Of those states, only Pennsylvania and posibly Oregon seem vulnerable.
Giving the GOP the "solid" South, (minus Virginia and Florida), the prairie states, and most of the Rocky Mountain states (less Colorado, Nevada, and New Mexico) gives them 176 votes. Most of those states seem solid for McCain, but the African American vote in the South may put at least Arkansas and Louisiana in play.
If that's the way it plays out, the election will come down to whether the GOP can carry Florida, Ohio, Virginia, Missouri, and Virginia. Loss of any one of those states gives the election to the Democrats. And even with all of them, McCain must still win Colorado and Nevada (or New Mexico) or West Virginia and Kentucky.
It's guesswork, of course, but I suspect that Virginia may be the key. If Obama can carry the state, perhaps with Jim Webb as a VP candidate, the odds tilt heavily against the GOP, regardless of what happens elsewhere.