Dick Cheney was a self-aggrandizing criminal who used his knowledge as a Washington insider to subvert both informed public debate about matters of war and peace and to manipulate presidential decisionmaking, sometimes in ways that angered even George W. Bush.
After his early years of public service, he capitalized on connections he made while being paid by taxpayers to earn tens of millions of dollars presiding over Halliburton. While there, he did business with corrupt Arab autocrats, including some in countries that were enemies of the United States. Upon returning to government, he advanced a theory of the executive that is at odds with the intentions of the founders, successfully encouraged the federal government to illegally spy on innocent Americans, passed on to the public false information about weapons of mass destruction in Iraq, and became directly complicit in a regime of torture for which he should be in jail.
Thus his unpopularity [13% Approval] circa 2008, when he left office.