Thomas Schaller’s prediction has come to pass:

By leaving the mainstream so decisively, the Deep South and Appalachia will no longer be able to dictate that winning Democrats have Southern accents or adhere to conservative policies on issues like welfare and tax policy, experts say.

That could spell the end of the so-called Southern strategy…. And the Southernization of American politics… appears to have ended.

“I think that’s absolutely over,” said Thomas Schaller, a political scientist who argued prophetically that the Democrats could win national elections without the South.

The Republicans, meanwhile, have “become a Southernized party,” said Mr. Schaller…. “They have completely marginalized themselves to a mostly regional party,” he said, pointing out that nearly half of the current Republican House delegation is now Southern.

And that’s just the present – the future looks even better.  Consider that the youth vote went for Obama by a margin of 2 to 1.  That the Latino community alienated by Republican racism and nativism is growing, and could ultimately turn Texas blue.  Which would pretty much be Game Over for the GOP.

So how will the Republican Party respond to these unfavorable trends?  Will they back off on their atavistic appeals to greed, fear, and hate, or will they double down?  I think David Brooks(!) offers the most realistic prediction:

To regain power, the Traditionalists argue, the G.O.P. should return to its core ideas: Cut government, cut taxes, restrict immigration. Rally behind Sarah Palin.

(…)

Congressional Republicans are predominantly Traditionalists…. Among the remaining members, the popular view is that Republicans have been losing because they haven’t been conservative enough.

(…)

Members of the conservative Old Guard see themselves as members of a small, heroic movement marching bravely from the Heartland into [the] belly of the liberal elite. In this narrative, anybody who deviates toward the center, who departs from established doctrine, is a coward, and a sellout.

Indeed, just as Brooks predicts, Republican SC Governor Mark Sanford argued today that the GOP simply needs to return to its conservative core principles of "lower taxes, less government and more freedom," while Michael Reagan is already calling for a return to the witch hunts of the Clinton era.  Yep, that should really restore the Republican brand, all right.

The GOP may eventually realize the error of their ways after a few more thumpin’s, but until then the Democrats have a golden opportunity to Get Stuff Done, provided they can find a way to keep the Blue Dog and Lieberman caucuses in line.  (Hint: taking away Joe’s cobwebby gavel would be a good start.)

But most important of all, they have to actually want to Get Stuff Done.  That’s what worries me, and that’s where Democratic half-assery and failure would open the door for the GOP to come roaring back.  If only we knew some people who could remind them that they have a mandate…