To a casual observer, the antics of both parties in Congress may resemble the monkey house at a zoo, rather than any attempts at systematic (let alone sensible) behavior. But these are rational men and women, and what they're doing is carefully designed to achieve specific goals.

Take the Democrats. They swept into control of both houses of Congress in November 2006, pledging to achieve all sorts of traditional Democratic objectives. In fact, however, they knew perfectly well that George W. Bush would continue to be president until January 2009, and that he could and would veto any highly partisan measures passed by the new Congress. Moreover, their narrow margin in the House and razor-thin edge in the Senate eliminated any possibility that they might be able to override any vetoes that thwarted them. So the Democratic Congress of 2007-08 was bound to be an exercise in political futility, at least in terms of achieving any meaningful legislation. The Democrats knew this, even if the American people did not. So they are concentrating on using these two years to advance their real objective, which is to capture the presidency in the 2008 election. In practical terms, this means making George W. Bush look bad.

The Democrats in control of Congress have two major means of furthering this end. The first is to introduce -- and, if possible, pass -- bills that sound attractive to the average voter but which they know President Bush will, for one reason or another, be sure to veto. That is the motive behind the various bills up for discussion, chiefly in the Senate but also in the House, which try (more or less seriously) to force the president to withdraw our troops from Iraq. The Democrats contend that the Congressional elections of 2006 resulted in a clear mandate from the voters to pull out of Iraq, and that Bush is simply defying the will of the people by refusing to do so.

They are probably wrong in attributing such a simplistic view to the voters, but they are undeniably tapping into a widespread public dissatisfaction with the war. Moreover, they can play innumerable variations on the general theme -- pull out now, "redeploy" in six months, limit overseas assignments, etc. Not one of these bills has passed, or is likely to. But harping on the subject serves as a useful reminder of which party supports the war, and which doesn't. (In the Senate, passage of controversial legislation is further restricted by the rule that permits even the minority party to filibuster to death any bill it dislikes, unless 60 senators vote to close off debate. Since the Democrats have only 51 votes, this is practically impossible.)

But Congress has one other powerful weapon in its quiver. By a simple majority vote, either house, or even a committee of either house, can decide to investigate just about anything it wants to, supposedly in furtherance of Congress's desire, and indeed obligation, to pass legislation. And, in order to investigate deeply, Congress and its committees are endowed with the subpoena power -- which is to say, the power to compel someone to appear before them and testify under oath, subject to the penalties for perjury. There are important limits to what Congress can compel officials of the executive branch to testify about. However, there are no limits to what an imaginative senator or congressman can at least demand. So Capitol Hill today is overrun with both regular and special investigative committees, probing all sorts of alleged misconduct on the part of various officials of the Bush administration. Most of these investigations won't get anywhere, and many aren't even intended to, but the liberal media can be depended on to treat them all as solemn inquiries into possible evildoing on the part of Bush's minions.

It's all great theater, as Senate Republican leader Mitch McConnell (Kentucky) said of majority leader Harry Reid's (Nevada) decision to keep the Senate in session all night to debate yet another doomed antiwar bill. And all the hullabaloo may even convince a few voters that the Democrats are really out there, trying to unearth wrongdoing and pass legislation for the good of the country.