Vivien Leigh was subject to bouts of depression and alcoholism and was abrasive to fellow actors. After a rocky start with her relationship with Lee Marvin with her complaints about his stale alcohol breath, the two eventually became highly unlikely good friends.
The election referred to was the German Federal election of 1933, in which the National Socialist German Workers Party (NSDAP, or the Nazis) received 43.9% of the overall vote, an increase of 10.8% on the previous election.
Oskar Werner and José Ferrer would make a similar film 11 years later. Voyage of the Damned (1976) also was about a boatload of refugees heading back to Germany before the outbreak of the Second World War. It would prove to be Werner's final film.