The ebb and flow of political life is exciting. We watch with the enthusiasm of a rabid sports fan. It is, in some ways, about more than policy. It defines a relationship between each citizen and the society at large.

As Republicans prepare for ascendancy we can take some comfort in a political time line with an arc longer than a single election cycle. Over the last three decades, we have seen the pendulum swing somewhat wildly. We have gone from a Reagan revolution, complete with the public smashing of the Democratic Party, followed by the victory of Bill Clinton. Then the Newt Gingrich-led re-revolution, and the political scandals that we all thought would topple a Democratic President. The squeaking victory of Bush, bought with some muscle in the vote counting in Florida, overturned a narrow expression of popular will for Gore. 9/11 brought back Republican victory, followed by two elections favoring Democrats. And, of course, there is Barack Obama. In November, Republicans will very probably take the House, perhaps the Senate. So if you don't like who's in office, you can wait a couple of years.

Except, except. Under the surface, a process hides. Each Democratic swing has been more pronounced. Each Republican turn has been weaker. GOP bluster has not been matched by numbers. There is a reason that goes beyond the "R" or "D" behind the name of electoral hopefuls.

Beginning in the 1990s, the underlying trend became pronounced. Thoughtful blogger Steve Benen catches the edge of it, but only the edge, in his review of a poll of Republicans. "The results were discouraging," he says. It is true on several levels. More Republicans want to see the President impeached than not. A large number buy the myth that he was born outside of the United States. A sizable percentage think he hates white people, and that he wants terrorists to win. A huge majority of Republicans say he is a socialist.

Benen links to politico for a silver lining: "One of the lingering questions is whether these extreme beliefs will push more reasonable voters away from the GOP." He understandably bemoans what he calls the megaphone gap. Voters at large don't seem to notice the extremism of the GOP.

It is that very gap that is, over time, dismantling what used to be the Party of Lincoln. Technology is the fuel. Cable and internet now give conservatives the ability to shield themselves from the day-to-day news coverage that we in the reality based community follow. The extreme John Birch Society type conspiracy belief system is an important symptom, but not the only one.

Moderates were expelled, and the influence of conservatives grew in their absence. Mainstream conservatives are being driven out, and their flight leaves the GOP in the hands of an ever bolder extreme element. The party shrinks as a consequence. It's been going on for a long time.

Need encouragement? Don't watch the waves. Watch the tide.