I don’t think he has run a particularly good campaign. Sure he has put in enormous effort in IA, but his message has not been in tune with the times. He talks way too little about how to fix the economy and way too much about his life and time in Congress.
I think people are desperate to hear solutions for the present and future, not rehash the past so much.
I seem to remember reading about someone losing a Senatorial election and two years later winning the Presidency. Oh yeah...Abraham Lincoln.