You can read Republican spin if you want, but you shouldn't believe it.
Fact is, Obama as an total unknown won the Democratic primary in 2004 -- that was the real upset. Illinois is a solid blue state, and after his speech at the '04 convention, I don't think his election was the fluke you make it out to be.
I also don't get all this hand-wringing about experience. We've elected two Presidents even younger than Obama, and they've turned out okay: T. Roosevelt and Kennedy. Eisenhower had no experience in elected office. Truman was an unknown minor senator and VP for just three months. Lincoln was a
one term congressman. On the other hand, Hoover had plenty of experience, as did Bush the elder. Experience is nice, but hardly essential, and a poor predictor of Presidential performance.
The whole point of the Obama campaign is, sure, the others may have experience, but it's
bad experience; it's the experience of getting us in the mess we're in.