First, Sir David talks to Sidney Blumenthal, a former adviser to Bill Clinton and now part of Hilary's campaign team.

He argues that Hilary still has a chance to win the nomination so she must stay in the race.

Blumenthal says John McCain, the Republican nominee, is a formidable candidate.

Also, new book by Darius Rejali, one of the world's leading experts on torture, puts the counter argument.

In Torture and Democracy, Rejali argues that the use of torture is futile.

Darius Rejali joins Sir David to discuss the issue. He says that torture does not produce good intelligence.

Rejali also says that modern democracies have pioneered forms of torture that leave few marks.