Robert Zimmerman, Jr. is the brother of George Zimmerman, who has been accused of second-degree murder in the shooting of Florida teenager Trayvon Martin.
Donna Brazile is a Democratic strategist, contributor to ABC News and CNN, and the Vice Chairwoman of the Democratic National Committee. This week she wrote an article outlining the GOP’s efforts to "restart, reform and rebrand."
Jon Meacham is executive editor and executive vice president at Random House and the author of Thomas Jefferson: The Art of Power. Read his contribution to the TIME cover story on the papal resignation here.
Comedian and actor Joel McHale will join the panel mid-show. He is the host of E!'s 'The Soup' and stars in NBC's 'Community.' McHale recently participated in a Reddit "Ask Me Anything," the result of which can be found here.