import copy


def remove_candidates(orders, candidates_to_remove):
  """
    Remove a set of candidates from a list representing a preference order.
  """
  projection = []
  for c_vote in orders:
    temp_vote = copy.copy(c_vote)
    for c_remove in candidates_to_remove:
      temp_vote.remove(c_remove)
    projection.append(temp_vote)
  return projection