From Longman Dictionary of Contemporary Englishtake/claim/seize the moral high groundtake/claim/seize the moral high groundto claim that you are the only person who does what is morally right in a situation, with the intention of being noticed and considered to be good by the public → moral
Examples from the Corpus
take/claim/seize the moral high ground• Some corporations have seized the moral high ground.• Television is therefore seen to be taking the moral high ground, the side of the punter against the forces of evil. 