Possible Clues:

• Following the difficult route, like GM protesters?
• How unwillingly the Corn Laws were passed?
• Has treating Gina badly been out of character?
• Rebelliously, perhaps (and a hint to this puzzle's four theme answers)
• Joiners sometimes saw this as contrary to natural inclination
• Possible summary of teetotaller's position contrary to natural inclination?
• Contrary to one's nature
• Another time straighten twisted wood — it's hard to work this way
• Boris Yeltsin's autobiography
• Out of character