Obama’s web team whipped up a frenzy this week with an edgy YouTube video imagining a victory by Sen. John McCain. They used archival footage of Tom Brokaw announcing the news, and the video climbed to the top of YouTube — besting celebrities, SNL clips and the Sarah Palin montages that dominate political hits at the web site. But this afternoon, NBC stripped the video off the web by filing a copyright claim with YouTube.

It’s a setback for Obama’s field program, which has used viral organizing to register and mobilize new voters.  The video promoted a dedicated voter portal, VoteforChange.com, that helps people register to vote.

It’s also bad time because there are only five days until the registration deadlines in the key states of Colorado, Florida, Ohio, South Carolina, Virginia and Georgia.