IT’S THE KOS-MOVEON EFFECT:

Democrats are getting an early glimpse of an intraparty rift that could complicate efforts to win back the White House: fiery liberals raising their voices on Web sites and in interest groups vs. elected officials trying to appeal to a much broader audience.

These activists — spearheaded by battle-ready bloggers and making their influence felt through relentless e-mail campaigns — have denounced what they regard as a flaccid Democratic response to the Supreme Court fight, President Bush’s upcoming State of the Union address and the Iraq war. In every case, they have portrayed party leaders as gutless sellouts. . . .

“The bloggers and online donors represent an important resource for the party, but they are not representative of the majority you need to win elections,” said Steve Elmendorf, a Democratic lobbyist who advised Kerry’s 2004 presidential campaign. “The trick will be to harness their energy and their money without looking like you are a captive of the activist left.”

Yep, that’s the trick.

UPDATE: Related thoughts here.

ANOTHER UPDATE: Bill Ardolino is congratulating Markos.

Also, a Watership Down comparison.