The first thing to be noted about Tuesday's election returns is that they were not, in any serious sense, a Democratic victory. They were, however, a thoroughgoing Republican defeat. The Democrats had practically nothing to do with it. They had no policy proposals to speak of -- least of all on Iraq, which they insisted was the central issue. But in a two-party system, if the voters decide to throw the rascals out, their only option is to throw the other rascals in. All the Democrats had to do was be there.

The Republicans have only themselves to blame. The candidates up for election were all members of Congress -- one third of the Senate, and the entire House of Representatives. Not surprisingly, the Democrats sought to turn the whole thing into a referendum on the war in Iraq, which is understandably unpopular but hardly the fault of Congress. But, to the extent that the voters chose to base their decision on matters for which the Republican leadership of Congress was indeed responsible, they can be forgiven for deciding to give the Democrats a chance.

In the 12 years since the GOP took control of Congress, they have settled down comfortably to "politics as usual," mimicking the performance of the Democrats during their 40 years in control. They cheerfully abandoned their conservative commitment to reducing government expenditures, racking up deficits that would have appalled Bill Clinton, and, actually, pushed the use of "earmarks" (whereby individual Congressmen can insert pork into legislation invisibly) to limits not even the Democrats had ever dreamed of. Inevitably, in this atmosphere, outright corruption ultimately made its appearance, and several Republican members of the House and their staff members are now in, or on their way to, prison.

What the Democrats will do with their newfound power is a question worth asking, provided you don't expect much of an answer. The truth is that, with Bush in the White House for another two years, and perfectly capable of wielding his veto pen, the Democrats couldn't impose their own policy agenda on the nation even if they had one. They can, to be sure, block Republican measures, and use the Congressional subpoena power to investigate and if possible pillory individual Republicans, but a divided government guarantees, for the next two years, what will amount to gridlock. And that may turn out to suit the American public very well.

It will, however, be fascinating to watch the unfolding of the struggle among the Democrats in Congress for control of the party's basic direction. In recent years, leadership of the Democratic party in Congress has devolved, inevitably, on those senior members who will now chair all of the powerful committees. These tend to be veterans from safe, ultra-liberal districts: Rangel in Ways and Means, Conyers in Judiciary, Dingell in Commerce, etc. Such men will see their newfound power as a way of leading the Democratic party to the left, and they can be depended on to try to do so.

But many of the Democrats elected to Congress for the first time this year are of a very different breed. They are, in many cases actually, conservative. That was how they managed to unhorse their Republican opponents, and there is no reason to suppose that they will abandon this highly successful posture now that they are in office. It is a safe bet that they will act as a major drag on the leftist impulses of their seniors. The battle will begin in Congress, but it will play out in the contest for the Democratic presidential nomination in 2008. Which is why that struggle for the soul of the Democratic party may determine its future -- and thus, to some extent, America's -- for many years to come.

As for the Republicans, we shall see how rapidly they can recover from their self-inflicted wounds. In the long run, everything depends upon their rediscovering, and recommitting themselves to, the great conservative principles that gave the GOP its long dominion over the nation. For that reason, the Republican party, too, will (like the Democrats) have to make, in 2008, a fateful decision about its future. Of these matters, more in my next column.