From Politico's Ben Smith:
Obama, at his Chicago press conference just now, lays out his path to the nomination, which depends first on having a majority of pledged delegates.
"If this contest comes down to superdelegates, we are going to be able to say we have more pledged delegates, which means the Democratic voters have spoken. Those superdelegates, those party insiders would have to think long and hard how they would approach the nomination," he said.
"The argument we would be making to superdelegates is, if we come into the convention with more pledged delegates then i think we can make a very strong argument that our constituencies have spoken and I think that's going to be pretty improtant when it comes to the general election," he says.