Although derided as an amiable dunce by his enemies, it is clear from recent research that his knowledge and intellect were far deeper than they imagined.
Although Mr Obama was at pains to stress her intellect, her long experience on the bench and her respect for the constitution, he made it clear that her background matters a lot to him.
First and foremost is a rigorous intellect, a mastery of the law, an ability to hone in on the key issues and provide clear answers to complex legal questions.