One of the most unambiguous conclusions from Obama’s victory? Karl Rove was right.

For the past 8 years, we’ve had a debate over the best political strategy for approaching a national election. There were, in essence, two contending theories.

Karl Rove’s theory – one he perhaps never explicitly articulated, but which was evident in the approach to multiple elections, votes in Congress, and even international coalitions run by his boss, George W. Bush – was, essentially, that you win with your base. You start with the base, you expand it as much as possible by increasing turnout, and then you work outward until you get past 50% – but you don’t compromise more than necessary to get to that goal.

Standing in opposition to the Rove theory was what one might call the Beltway Pundit theory, since that’s who were the chief proponents of the theory. The Beltway Pundit theory was, in essence, that America has a great untapped middle, a center that resists ideology and partisanship and would respond to a candidate who could present himself as having a base in the middle of the electorate.

Tonight, we had a classic test of those theories. Barack Obama is nothing if not the pure incarnation on the left of the Rovian theory. He ran in the Democratic primaries as the candidate of the ‘Democratic wing of the Democratic Party.’ His record was pure left-wing all the way. He seems to have brought out a large number of new base voters, in particular African-Americans responding to his racial appeals and voting straight-ticket D. As I’ll discuss in a subsequent post, the process of getting to 50.1% for a figure of the left is more complex and involves more concerted efforts at concealment and dissimulation, but the basic elements of the Rovian strategy are all there.

John McCain, by contrast, was the Platonic ideal Beltway Pundit-style candidate, and his defeat by Obama ensures that his like will not win a national nomination any time soon, in either party. McCain spent many years establishing himself as a pragmatic moderate, dissenting ad nauseum and without a consistent unifying principle from GOP orthodoxy; McCain had veered to the center simply whenever he felt that the Republican position was too far. McCain held enough positions that were in synch with the conservative base to make him minimally acceptable, but nobody ever regarded him as a candidate to excite the conservative base.

Now, it’s true enough that the partisan environment was terribly challenging for Republicans in 2008. That’s why so many of us on the Republican side were willing to go with McCain in the first place. But here’s the thing: if you believed the Beltway Pundit theory, that shouldn’t matter. If a significant and reliable bloc of voters consistently preferred the moderate, centrist candidate over the more ideological and partisan candidate, in the same way that conservatives prefer the more conservative candidate and liberals prefer the more liberal candidate, you would have a base from which a candidate like McCain could consistently prevail against a candidate like Obama, and partisan identification would be trumped by moderation and proven bipartisanship.

But there is no such base. Centrist, moderate, independent, voters are generally “swing” voters, always have been and always will be. Among those who are at least modestly well-informed, they are a heterogenous lot – some libertarian, some socially conservative but economically populist, some fiscally conservative and socially liberal, some isolationist and anti-immigrant, etc. It’s not possible to make of them a “base” – the only way to approach the center is to lock down the real base at one end or the other of the political spectrum, and then reach out to voters in the middle, understanding the real tradeoff that what appeals to one “swing” voter may be anathema to others.

Of course, the dismal approval ratings of the Bush Administration at the end of its days testify to the serious arguments over whether Rove and his boss chose the wrong mix of reaches out to the center as they built their “compassionate conservative” coalition; that’s a separate debate. It is likewise a fair debate over the ways in which future conservative candidates can and should make compromises to get the GOP back to that 50.1%. But what’s not open for debate, after tonight, is the sheer futility of trying to build a coalition from the center out. Because the center won’t stand still for any candidate.