IDIOMS

turn the scale

(idiomatic) To turn to one side a balanced situation.

Example: 1919, W. Somerset Maugham, The Moon and Sixpence, ch. 1
  Perhaps Charles Strickland's power and originality would scarcely have sufficed to turn the scale if the remarkable mythopoeic faculty of mankind had not brushed aside with impatience a story which disappointed all its craving for the extraordinary.