What's at stake in the US election: Control of Congress

At stake in this election is not just which party controls the White House, but who has a majority in the House of Representatives and the Senate.

When Americans go to the polls they do not just elect their next president, but every single member of the House of Representatives and a third of US senators.

Rajini Vaidyanathan explores why these "downballot" races matter.

Video by Franz Strasser. Produced by Mat Morrison.