Some interesting thoughts on how the Iron Law of Institutions plays out in the Democratic Party from Chris Bowers
Thinking back over the past decade and applying this line of thought to the major progressive electoral challenges, it seems pretty obvious now that centrist Democratic elites are far, far more threatened by attempted progressive take-overs of the Democratic Party than they are by progressive threats of third party splits. There was tremendous elite hysteria over Nader in 2000, Dean in 2004, and Lamont in 2006, but the nature and outcomes of that hysteria was different. First, Nader in no way threatened the power of Democratic leaders within the Democratic Party, and only threatened the power of the Democratic coalition relative to the Republican coalition. This is probably why there was as much, if not more, Democratic activist anger at Nader and his supporters than there was elite Democratic attacks against him. Further, unlike the Nader 2000 campaign, the Dean and Lamont campaigns were supported by significant institutional power, including large unions, the blogosphere and MoveOn.org. In other words, the Dean and Lamont campaigns scared many Democratic elites way, way more than the Nader campaign, because they represented large institutional forces making a serious bid for control of the institution of the Democratic Party itself. By comparison, a generally non-institutional campaign that threatens only to tip the balance of power between the two major coalitions is not nearly as serious a long-term concern, especially when it can only muster less than 3% of the popular vote. Both in polls before their elections and on Election Day itself, Dean and Lamont scored a lot more than 3%.
And from A Tiny Revolution
If you want to motivate powerful Democrats, attempt to threaten their power within the party, not the well-being of the party overall. Of course, this is easier said than done, particularly because much of the power within the party is (as Karp would put it) an unelected Democratic oligarchy. For instance, Pelosi's status as Speaker can be challenged straightforwardly. Getting at the source of the party oligarchy's power, which is money and institutions outside of electoral politics, is much more difficult.