New Republic’s Dana Goldstein describes the war between Clinton and Obama supporters in the blogosphere.

These people are not pretty when they’re angry.

As anybody with high-speed Internet knows, MyDD and Daily Kos sit at the top of the liberal Netroots movement, which over the last five years has made astonishing strides in its campaign to transform the Democratic Party into a hard-fighting, proudly liberal, and, most importantly, victorious entity. Though their websites offer distinct communities and commentaries, and though they have very different personalities, MyDD founder Jerome Armstrong (a former astrologer) and Kos’s Markos Moulitsas (a former Army man) have always gotten along–the two co-authored a 2006 book, Crashing the Gate, about the rise of their movement. Their bond has been rooted mostly in common foes: Republicans, namby-pamby Democrats, the Iraq War, divisive “identity politics,” and the centrist Democratic Leadership Council. But the harmony that existed between MyDD and Kos since the birth of the Netroots no longer exists today, and a bitter internecine struggle within the progressive blogosphere is to blame. Just as bilious in tone as previous fights with Republicans or Joe Lieberman, it has revealed fault lines in the movement that will be tough to cover back up. There have been charges of misogyny and of bullying, and some longtime members have walked away from their cause altogether. And what’s at the heart of it all is that most loaded of questions: Barack or Hillary?

The Netroots have been arguing about the 2008 campaign since the day after John Kerry lost, but the debate turned ugly when Armstrong revealed his vote in the February 12 Virginia primary. “In the end, what compelled me to vote for Clinton was looking at someone that seemed practical about the battle we have on our hands and looking ready to engage in the fight,” Armstrong blogged that day. “I’d rather be part of the fight than be told to stay on the sidelines because I’m too partisan.”

Armstrong had long voiced concerns that Obama’s campaign was too personality-driven and too reliant on the votes of Independents and Republicans. But his official endorsement made readers go ballistic. “Voting for the DLC candidate makes you part of the fight? Come on,” wrote one commenter. Another suggested, “If you aren’t a part of her campaign, you really oughta try to sign up and get some of those $$$ while you can”–a dig at Armstrong’s past campaign work for politicians like Howard Dean, Jon Corzine, and Mark Warner. A group of far nastier comments were deleted.

At Daily Kos, commenters were ripping Armstrong to shreds. One user wrote, “MyDD isn’t even a pro-Clinton site these days. It’s just a toxic waste dump dedicated to throwing slime at Obama and hoping it sticks. … I know that Kos and Jerome are friends and partners, but it’s perhaps time for Kos to reconsider linking to MyDD from the DK blogroll.”

Clintonites and Obamabots were ferrying between the two sites, “recommending” posts sympathetic to their favored candidate (thus ensuring more prominent placement on the page), and brutally attacking one another in the comment sections. In late March, Armstrong, upset by name-calling between Clinton and Obama supporters on MyDD, barred new user accounts on the site for a week. The sense of betrayal among fellow Netrooters after his Clinton endorsement was palpable. Armstrong was backing a candidate who, as Chris Bowers, another leading lefty blogger, wrote on Open Left, hadn’t fully rejected the DLC, hadn’t opposed the Iraq war from the start, hadn’t offered overwhelming support for Net Neutrality, and hadn’t campaigned in small caucus states.