Possible Clues:

• Curious boy tracks what happened before start of film
• It ensures well-rounded character votes for Boris?
• Fictional past, or a hint to four-letter words found in the starred answers
• Character's previous life
• Helps to track earlier episodes
• The chiropractor's strong suit was a good ___
• Supports British politician in the plot before now
• Supports politician — it's happened before now
• Supports Boris, perhaps -- is this in anticipation of plot?
• Account of previous events supports politician