Michael Barone looks at the Georgia Senate runoff and finds:

The Obama campaign did a magnificent job of turning out black voters in rural and small-town counties in Virginia, North Carolina, and Georgia for the November 4 election. But it was not able to replicate those results in the Georgia runoff. Black turnout pretty much matched white turnout in the inner Atlanta area, where black political organizations have been active for many years, but it failed to do so in the outer suburbs with increasing black majorities and in North Georgia counties with few blacks. Black turnout did match statewide levels in black-majority cities in southern Georgia, but not enough to outweigh similar white turnout in adjacent suburban counties.

What does this mean for the future? Barone writes:

That suggests another hypothesis: that the Obama turnout effort among blacks may not be replicable. You can only vote to elect the first black president once. . . But the results here do suggest that other Democrats will have a hard time duplicating Obama’s percentages in affluent suburban counties. Note that this runoff took place when opinion is very favorable to Obama and when he has been getting credit for bipartisan or at least nonpartisan appointments (Robert Gates, Timothy Geithner).

Some will say, “But this was Georgia!” Yes, if it had been Florida, Ohio, or Colorado the story could well have been different. But, by the same token, query how Libby Dole in North Carolina would have fared had she been running, as Chambliss did, without Barack Obama at the top of the opposing ticket. So it is not just geography which counts. It’s context, which was amplified in the general election by the GOP’s George W. Bush drag and the Democrats’ Barack Obama lift.

In 2010 there won’t be George W. Bush to kick around anymore. And the most important factor–the economy–may not play in the Democrats’ favor as it did in 2008. The economy (it will be by then the Obama economy) will either be improved, about the same or worse. Unless it is the first, Democrats will have little cover. And turnout is likely to be a far cry from 2008. All of that may serve to re-level the playing field, provided the Republicans recruit viable candidates and have an attractive message (two very big question marks).

So, once again we are reminded: nothing is permanent in American politics. And the party in power better perform.