high and mighty vs on one's high horse

high and mighty

noun
  • A social or economic group wielding undue power, influence or economic clout. 

adj
  • Ever since she was placed in the gifted program, she's become so high and mighty that no one wants to be near her. 

  • Overbearingly arrogant; ostentatiously self-important or self-aggrandizing. 

on one's high horse

prep
  • Self-righteous; proceeding on the belief one is more correct or proper than others. 

How often have the words high and mighty and on one's high horse occurred in a corpus of books? (source: Google Ngram Viewer )