Obama's Crowd Has to Concern Hillary

Barack Obama made his big announcement, and drew quite a crowd:

Though it was frigid in Springfield, IL this morning, local police estimate there were between 15,000 and 17,000 people at Sen. Barack Obama's campaign kick off.
And though we've known he was running for several weeks, the Chicago Tribune notes Obama's "official launch still generated extraordinary interest in his 21-minute speech. By one count, 523 media credentials were issued, with dozens of international outlets included. His announcement was the lead story on the afternoon broadcast on BBC radio."

Although Obama was in his home state, I don't remember Hillary drawing any crowds like that anywhere she's been. That turnout has to be a great concern to her campaign bigwigs.