David Greenberg: 

In recent weeks, there’s been a giddiness in liberal circles when the subject of the 2008 presidential election comes up. You can feel a buoyancy, an expectation that this will finally — inevitably — be the Democrats’ year.

To many people, it seems self-evident: The war in Iraq has become a debacle, and Al Qaeda has regrouped. President Bush’s approval ratings are dismal (between 26 and 33 percent in various July surveys). The Republican party is imploding, as each month some new species of malcontent — a Christian traditionalist, a tax cutter, a libertarian — gripes that Bush has abandoned “true” conservatism. In Congress, the party has sundered over not just the war but also Bush’s top domestic priorities, most notably immigration reform. And no GOP presidential candidate has emerged, as Bush did in 2000, to unite the rancorous factions, including the ever-important religious right.

Meanwhile, the Democrats, fresh off their 2006 capture of both the House and the Senate, appear stronger than at any time since before 9/11. More voters identify as Democrats than as Republicans. More unexpectedly, as The Wall Street Journal reported on its front page last week, the party’s presidential candidates have raised $100 million more than their GOP rivals. Not for nothing have two of the sharpest political analysts around, John B. Judis and Ruy Teixeira, written a cover story for the liberal magazine The American Prospect asserting that the “emerging Democratic majority” they foresaw in 2002 is finally at hand.

In short, how can the Democrats lose?

Easy. The Republicans possess certain advantages that are too often overlooked, including a built-in edge in the electoral college, Bush’s impending exit from the political picture, and several candidates with potential across-the-board appeal. The Democrats have improved their national fortunes since the 1990s by getting swing voters to return to their fold, but on the Iraq war, the party at times seems to be echoing its Vietnam-era posture on national security, when it lost the nation’s trust on matters of war and peace. Such a course could alienate independent and centrist voters all over again and usher in another four years of Republican rule.

The first myth to dispel is that of Democratic momentum. It’s tempting to regard the Democrats’ 2006 triumphs as rock-hard proof that a new liberal wind is blowing. But as a historical matter, the party that wins the Senate or House in an off-year election has no discernible advantage when seeking the presidency two years later.