WASHINGTON — Resolving modern-life social and legal issues by applying a constitution drawn up over 200 years ago is a tough and ever evolving challenge, says US Supreme Court judge Stephen Breyer.

"George Washington knew about commerce between the states, he did not know about the Internet," Breyer told AFP in an exclusive interview, as he looked back on his 18 years serving as one of nine judges on the nation's top bench.

"But we have to apply the values that underlie free speech to a world with the Internet, to a world with television.

"The difficulty of a constitutional judge's task is to work out how these values, embodied in words in the document (the Constitution), these values that do not change, how do they apply to circumstances that continuously change?

"And that kind of problem comes up all the time," said this pragmatic judge, counted among the more liberal, progressive members of the bench.

The Supreme Court does battle with some of the most complex and perplexing questions bedeviling modern life, basing every decision on the US Constitution written in 1787 by the nation's founding fathers.

The nine judges -- who are appointed for life -- have tackled everything from abortion to campaign financing, to whether under the Freedom of Speech amendment a teenager can wear a shirt saying "Bong for Jesus" at a school event or an evangelical church can picket strangers' funerals carrying hate-filled anti-gay slogans.

In 2000 it decided the outcome of the presidential election, ruling that George W. Bush had won over Al Gore, forever changing the destiny of the United States and its footstep on global geopolitics.

And this year it will rule on whether to strike down President Barack Obama's signature health care reform -- a decision that could roil the 2012 elections.

But at the heart of most issues, says the 73-year-old Breyer, is "how should this document relate to ordinary Americans, how?"

"And those very basic views, reflecting your background can differ from one person to another. And they do. And that kind of thing explains the differences, I think, very well, much better than politics."

Despite the 2000 Bush v. Gore decision, this Harvard and Oxford University trained lawyer and father of three insists that the rulings of the court -- which has the final say on such weighty matters -- are not colored by political constraints or opinions.

"That isn't politics, that is different ways of seeing the world and in so far as they affect law, you might see them reflected in opinions, that's okay. Nothing wrong with that.

"We're a very big country. 309 million... including the lawyers... of course people have different views. There is every race in this country, every religion, every point of view, and through some miracle, they decided to live together under law. Well that's fine, that's wonderful.

"And if there should be some of those differences of view reflected in people's basic philosophy or jurisprudence on that court, nothing wrong with that."

Breyer, a fluent French-speaker with a ready and courteous smile, who was appointed to the court by then president Bill Clinton, believes the constitution is there to uphold basic values cherished by every American.

"Each of these words -- freedom of expression, freedom of speech, of religion -- they express underlying values, those values, basic to a human beings, don't change very much over time, they are fixed. But the circumstances change every five minutes."

He acknowledges many decisions -- such as the 2010 five-to-four majority ruling to loosen campaign finance rules -- can be controversial.

Breyer was among the four judges who voted against opening up campaign funding to independent corporations, a decision that has handed rich political action committees huge sway over the current White House battle.

"I try to decide the cases the best I can. That's what judges do. And then journalists, or law professors, or others can say whether they consider that liberal, or conservative, or whatever they want to say."

Turning to speak in French, Breyer added: "President Jefferson said that the problem with the Supreme Court is that they never retire, and they rarely die.

"It's very long, but at the same time, it's very difficult to put political pressure on a judge."

He and his colleagues seek not to be subjective in their decisions, but at the same time in interpreting the constitution "we worry about rigidity."

And he takes issue with one stream on the bench that believes in a very strict adherence to the constitution, sticking to its every word.

"Why do other people want to say, 'Do everything via history?' I say, that won't work... If you want just history, let's hire nine historians. Let's not hire nine judges."

For this esteemed judge, disagreement within the court, which he says returns unanimous decisions 40 percent of the time, is part of the healthy process of a democracy in action.

"The nine judges here get on very well personally, very well," he insisted.

But dissent can prove a useful means of trying to sway colleagues to modify their own points of view.

"I'm always writing a dissent not for you, and not for the public. My audience is always the other judges. And they will read it. And I'm hoping that there'll be some changes. And sometimes there are, you see -- more than you think. And then the dissent has succeeded."