Jonathan Rauch, one of my favorite political journalists, has a theory about why Obama and the Democratic Party are flailing right now. It's not a new theory, but the current political climate is another piece of real world evidence to support what might seem at first to be a counterintuitive supposition.

Rauch believes that the fact that the Democrats control both the White House and Congress is hurting them. He believes it would be more productive if the Democrats lost control of Congress and divided control of government.

The question is, how could things have gone south so fast? The economy is clearly a factor, but the economy was even worse a year ago, when Obama was popular and hopes were high. He made mistakes, but politicians always do. This column, while not dismissing situational explanations, asks you to consider a further possibility: Unified government makes the country virtually ungovernable.

Like a lot of people, I have believed for quite some time that power-sharing (one party controls the White House, the other at least one chamber of Congress) works better. The voters prefer it, having split control in 23 of the past 30 years. The two most politically successful and popular recent presidents, Ronald Reagan and Bill Clinton, shared power for most or all of their terms; the most widely reviled of recent presidents, George W. Bush, saw his popularity collapse when Republicans won total control. Reforms win broader acceptance and are more durable when both parties' fingerprints are on them. The two great domestic reforms of their respective eras, tax reform in 1986 and welfare reform in 1996, were products of divided control.

All of that you have heard before from me and others. Recently, however, watching the neck-snapping speed with which a backlash has formed against Obama's all-Democratic government, I have become convinced of a stronger proposition: In practice, the difference between divided and unified control has become so stark that we should think of them as being, for practical purposes, two distinct systems of government -- if you will, binary government. Though the country has only one Constitution, it has two governability settings. Call them Mode 1 (one-party control) and Mode 2 (two-party control). Power-sharing is the switch that toggles between them.

Rauch goes on to explain that the fundamental problem is that we have two parties whose centers are both too far away from the country's center, its moderate independent segment which forms the critical swing votes in any election, and neither party has enough of a majority to pull off any legislation on their own. When one party controls both Congress and the White House, the other party withholds all its support, it has no incentive to work with the other side. This means the governing party has to govern from its center, but that's still too far off what moderate independents consider to be their center. If they revolt, a majority can't be foundThis is what has killed healthcare reform.

But if the parties share control, compromise is the only way to pass legislation. This acts as a natural pull towards the country's true center, thus pleasing centrist independents. The math works out now.

Rauch admits he has no proof that this theory is true, but he pulls many examples from the last 30 years that support it. A fascinating read, and one that should hearten those who are despairing at repeats of the Massachusetts election leading to a Republican Congress.

politics, jonathanrauch