HARDtalk

This week Barack Obama had a chance to take a decisive lead in the race for the Democratic nomination for President. But it didn't happen. Hillary Clinton advertisements may have stemmed the Obama tide when they asked, 'who do you want in the White House when the phone rings at 3 am?' Samantha Power is Barack Obama's senior foreign policy advisor. Stephen Sackur asks her if his inexperience in world affairs is catching up with him.