David Rubenstein — the billionaire philanthropist and co-founder of the Carlyle Group — interviewed four of the six living presidents for "The Highest Calling," his new book out Sept.

WASHINGTON - David Rubenstein ... His new book is about the American presidency. It's called "The Highest Calling," and it ...

David M. Rubenstein is cofounder and co-chairman of the Carlyle Group, one of the world's largest private equity firms, with offices in the United States, Europe, Asia, and Japan. Prior to ...