He made the comments today in response to a question about trade.
"The issue with respec to myself and Elizabeth," the president said with a grin, "has never been personal. It's fun for the press to see if we can poke around at it--when you see two close allies who have a disagreement on a policy issue. But there are a whole bunch of some of my best friends in Senate as well in the House, some of my earliest supporters, who disagree with me on this. And I understand it."