Did Arlen Specter mean to say that Clarence Thomas doesn't count as a black person?

On "Meet the Press," David Gregory questioned Arlen Specter about who President Obama should pick to replace David Souter on the Supreme Court:

SEN. SPECTER: He should be looking for someone with a strong academic and professional background. It would be my hope that he would choose someone with diversity. Women are underrepresented on the court. We don't have an Hispanic. African-Americans are underrepresented. I would hope that he would look beyond the circuit courts of appeals which now populate the Supreme Court and pick someone with greater world experience and diversity.

African-Americans are underrepresented on the Supreme Court? There is 1 African-American on the Supreme Court, which has 9 Justices. 1 is 11.1111 percent of 9. 2 is 22.2222 percent of 9. African-Americans make up 13.4% of the U.S. population. Is Arlen Specter ignorant of these facts, or does he mean to say that Clarence Thomas doesn't count as a black person?

In answering the question, take this into account: