Barack Obama has laid out his strongest message so far on the suggestion that he should be considering the Vice President position on a ticket with Hillary Clinton.
"With all due respect, I've won twice as many states as Senator Clinton. I've won more of the popular vote than Senator Clinton. I have more delegates," he said. "So I don't know how somebody who is in second place is offering the Vice Presidency to the person who is in first place."
Speaking in Mississippi ahead of today's vote, Obama went on to question the logic that applied to the Clinton position.
"I don't understand," he said. "If I'm not ready, how is it that you think I would be such a great vice president? Do you understand that?"
Polls show that Obama should win comfortably today in Mississipi, with some pollsters having him on as much as 60% of the vote.
A big win there will give him an even bigger lead over Clinton, making the Pennsylvania contest even more important.