Professor
Iwan Morgan (UCL Institute of the Americas) discusses what might happen if a US
presidential candidate is no longer able to stand for election due to ill
health.
Watch: BBC 2 'Newsnight' (from 23 mins 45 secs),
Listen: BBC Radio 2 'Steve
Wright in the Afternoon' (from 1 hour 1 min 27 secs),
Read: Deutsche Welle