Kos loses it:

Once upon a time, party officials feared NARAL, they feared the unions, they feared the Sierra Club, they feared trial lawyers, they feared NOW, they feared the NAACP, they feared Latino groups, and so on. For the first time, it looks like they're starting to fear people, not special interest groups. We're growing up as a party.

Wal-Mart is a special interest because it leverages a tremendous amount of money and power to serve narrow ends which benefit a tiny constituency of plutocrats and wreak havoc on the lives of most Americans. Unions pool and leverage the power of their members and their willingness to engage in organizing and collective action to secure justice for themselves and for millions of working Americans. There is no comparison. To say that bevy (however large) of bloggers (folks who are disproportionately whiter, richer, and maler than America, let alone the Democratic party) are real people in a way that organized workers, organized environmentalists, organized women, and organized people of color are none is outrageous.