In its political analysis, the progressive blogosphere tends to focus, understandably, on the Democratic Party -- how can it mount a more effective opposition? What strategies can it use to return to power?

But the weakness of the Democrats, though important, is not the most critical feature of today's political scene. The central domestic political problem is a Republican Party that has been wholly captured by the extreme right, what used to be called "the lunatic fringe."

Democrats can argue all they want about whether they should "move toward the center" or "satisfy their base." The fact remains that until the Republican Party moves toward the center there will be practically no hope of restoring humane or even minimally competent government to this country for any length of time.

Even if the Democrats do well in this year's off-year election and spectacularly well in 2008, the Republicans will probably still be in a position to hamstring and wreck any Democratic initiatives. The extremists of today's Republican Party have shown themselves willing to go to any lengths, including breaking the law, to ensure the failure of the opposition. Should the Democrats win the Presidency in 2008, we are likely to see obstructionist tactics so extreme that the days of the Clinton Administration will come to be remembered as an era of bipartisan bonhomie.

And of course the Democrats will not be able to hold power indefinitely. Then the Republicans will come back in with their wrecking ball. As we have seen in the past six years, it is much easier to destroy the underpinnings of competent, let alone progressive, government than it is to put them in place.

The advances of the New Deal/Great Society era were not merely the product of Democratic hegemony. Starting with the Eisenhower Administration (and probably before that with the nomination of Wendell Wilkie) it became clear that the Republican Party was not going to give in to its fringe wing of Roosevelt-haters, John Birchers, Minutemen and Liberty Lobbyists. The Republicans became then what they have not been since at least 1994, a responsible voice for conservatism.

Because the Republican Party today is not a conservative party but a party of reactionary extremism, and because it is one of the two major parties in a two-party system, the outlook for any kind of progressive agenda will be dim until the Republican Party reforms itself.

It is barely an overstatement to say that the Republicans must go through a process equivalent to "de-Nazification" before they can again become constructive participants in national politics.