"We're the boundary patrol," Breyer said, reiterating themes in his 2005 book that argue in favor of affirmative action in university admissions, because they would lead to diverse workplaces and leadership.
"It's a Constitution that protects a democratic system, basic liberties, a rule of law, a degree of equality, a division of powers, state, federal, so that no one gets too powerful," said Breyer, who often votes with a four-member liberal bloc of justices.
In the interview taped for broadcast yesterday on "Fox News Sunday," Breyer said that in some cases it would not make sense to strictly follow the Constitution, because phrases such as "freedom of speech" are vague.
He said judges must look at the real-world context -- not focus solely on framers' intent, as Justice Antonin Scalia has argued -- because society is constantly evolving . He said the founders' references to "freedom of speech" don't say how they should be applied to the Internet.
Pointing to the example of campaign finance, Breyer also said the court was right in 2003 to uphold on a 5-to-4 vote the McCain-Feingold law that banned unlimited donations to political parties.
Acknowledging that critics had a point in saying that the law violates free speech, Breyer said the limits were constitutional because it would make the electoral process more fair and democratic to candidates not tied to special interests.
Breyer, who has voted to uphold abortion rights, declined to comment on the court's role in deciding abortion. Justices are considering the constitutionality of a procedure some call "partial-birth" abortion.
