Jim Henley thinks so:
I think there’s a passion for Hillary Clinton’s candidacy that’s almost as invisible to the Democratic-Party netroots as Karl Rove’s vote drive among evangelicals was in 2004. Only very occasionally does this passion glimmer into the view of the progressive blogosphere. My claim is basically that the Clinton voters are out there mostly nursing their allegiance quietly, like the classic quiet conservatives keeping their opinion to themselves until they get into the voting booth.
Clinton's supporters are more anti-war than Obama's and more classic working-class Democrats. Go figure.
(Hat tip: Matt.)