Going into the 2004 election cycle, just about everyone said the Internet was going to change politics. But no one was sure how. Now we know.

The first signs of change came from the Howard Dean campaign. His campaign manager, Joe Trippi, used the Internet, and meetup.com and moveon.org, to identify and bring together Bush-haters from all over the country and raise far more money than anyone expected.

Dr. Dean rose to the top in the polls and amassed an e-mail list of 600,000 names. When Democratic voters dropped Dr. Dean as unelectable and embraced John Kerry as the most readily available instrument to beat George W. Bush, Mr. Kerry inherited Dr. Dean’s Internet constituency. No one expected the Kerry campaign to raise more money than the Bush campaign. But it did, largely because of the Internet.

The Democratic Internet constituency was and is motivated by one thing more than anything else: hatred of Mr. Bush. To see that, you only have to take a look at dailykos.com, run by Democratic consultant Markos Moulitsas, which gets 400,000 page views a day – far more than any other political Web log – and which received funding from the Dean campaign (which Mr. Moulitsas disclosed). It seethes with hatred of Mr. Bush, constantly attacks Republicans, and excoriates Democrats who don’t oppose Mr. Bush root and branch.

When four American contractors were killed in Iraq in April 2004, dailykos.com wrote: “I feel nothing over the death of the mercenaries. They are there to wage war for profit. Screw them.”

This repulsive comment produced no dropoff in page views. This was what the left blogosphere wanted. Kos was an early enthusiast for Dr. Dean’s campaign for Democratic chairman and disparaged other candidates.

For 12 years, Democratic chairmen were chosen by Bill Clinton. He built a new generation of fund-raisers who relished contact with the Clintons. Now, the big money comes from the left blogosphere and Bush-hating billionaires like George Soros. Dr. Dean gives them what they want.

As Dr. Dean says, “I hate the Republicans and everything that they stand for.” Hate. But Bush-hatred was not enough to beat Mr. Bush in 2004 – Democratic turnout was up, but Republican turnout was up more – and doesn’t seem likely to beat Republicans in 2006 and 2008. The left blogosphere has driven the Democrats into an electoral cul de sac.

The Bush campaign, quietly, used the Internet to build an e-mail list of 7.5 million names and a corps of 1.4 million volunteers, who produced more new votes than the Democrats. But the right blogosphere was different from the left. There was no one dominant Web site and no one orthodoxy.

Glenn Reynolds, the University of Tennessee law professor whose instapundit.com gets 200,000 page hits a day, supports Mr. Bush on Iraq but disagrees with him on abortion, stem-cell research, and same-sex marriage. The focus of hatred in the right blogosphere is not Mr. Kerry or the Democrats, but what these bloggers call Mainstream Media, or MSM. They argue, correctly in my view, that the New York Times, CBS News, and others distorted the news in an attempt to defeat Mr. Bush in 2004.

The right blogosphere’s greatest triumph came after CBS’s Dan Rather on September 8 reported that Mr. Bush had shirked duty in the National Guard and the network posted its 1972-dated documents on the Web.

Within four hours, a blogger on freerepublic.com pointed out that they looked as though they were created on Microsoft Word; the next morning, Scott Johnson of powerlineblog.com relayed the comment and asked for expert views. Charles Johnson of littlegreenfootballs.com showed that the documents exactly matched one he produced using default settings on Microsoft Word. CBS defended the documents for 11 days, but finally confessed error and eased Mr. Rather out as anchor. MSM tried to defeat Mr. Bush, but succeeded only in discrediting itself. The Pew Center’s post-election poll showed a sharp decline in the credibility of newspapers and broadcast TV, and a sharp increase in reliance on cable news, especially Fox News, and radio.

So what hath the blogosphere wrought? The left blogosphere has moved the Democrats off to the left, and the right blogosphere has undermined the credibility of the Republicans’ adversaries in Old Media. Both changes help Mr. Bush and the Republicans.