I could (and have) write a long dissertation why things are much worse for President Obama than people like NBC would have you believe, but here's a short two-pointer:
1. There is a huge "lie factor" in play here. Especially among Obama's core, minority demographics. They tell pollsters what they think the "party" would want them to say but will vote otherwise.
2. There is a marked drop in enthusiasm. People who would brave rain, snow and sleet to vote for "The One" in 2008 will now find other things to do like wash their hair or vacuum the dog rather than bother to vote. Some may even switch allegiance. Either way it will hurt Obama.