The contemporary "Internet left" is not very left. It is vociferous, partisan, and alert to opportunities to nail Republicans and Joe Lieberman. And there's nothing wrong with that. But left? Please.
The netroots were forged in the heat of the 90s, of Clintonism, of triangulation. We are, largely, an empiricist, unideological movement -- part of Clinton's Democratic Party, even while there's a conscious effort to break away from his fetishistic centrism. The radicalism, such as it is, exists in tone, buttressed by a few signaling policy tests. Iraq, for instance. And health care. But outside of Sirota, there's very little talk of trade, and very few who reflexively question the 90s model of globalization. Unions have begun to penetrate more deeply into the online consciousness, but not hugely so. When TPM Cafe tried to start a Labor blog, it fell apart in a couple of months. There's little appetite for fundamental government intervention in the economy, or enduring pacifism abroad.
In essence, we're on the leftmost edge of the mainstream consensus on most, though not all, issues. American power can be good but Iraq is bad. Free trade is good but CAFTA is bad. The free market is good but relatively poor at providing health care. Etc, etc. Now, those all might be the right positions. They're certainly my positions, so don't think I'm exempting myself here. But they're not "a left," certainly not in the way the NeoCons and the libertarians compose the country's right.