Watch Now: Barack and Michelle Obama electrify Democrats but warn of tight race

Michelle and Barack Obama gave resounding endorsements of Kamala Harris on Tuesday night at the Democratic National Convention, exhorting party supporters across the US to turn out and vote to defeat Donald Trump in November.
"Hope is making a comeback," Mrs Obama told the crowd at the DNC in Chicago, echoing her husband's campaign promise of "hope and change".
In their back-to-back speeches, the Democratic Party's most popular figures praised Ms Harris, while excoriating Trump - whose presidency was characterised by "bluster and chaos", in the words of Mr Obama.