Stephen Sackur speaks to Valerie Jarrett, former advisor to President Obama. It is one of the great puzzles of American politics; how voters could make history by putting Barack Obama in the White House - twice - and then elect Donald Trump as his successor. How much responsibility should team Obama take for the course American politics has taken since they left centre-stage? Valerie Jarrett is a close friend and advisor to Barack and Michelle Obama from early days in Chicago, all the way through the White House years. How will historians view the Obama legacy? Show less