“Whereas in democratic countries the businessman may use his money to influence legislation and public opinion and thus operated as a source of power and corruption, in fascist countries he can exist only as the subject upon whom State power operates. The corruption in fascist arises inevitably from the reversal of the role of the capitalist and the State as wielders of economic power.”

The United States (1971)

Source: Freedom from Fear (1991)
Context: It is not power that corrupts but fear. Fear of losing power corrupts those who wield it and fear of the scourge of power corrupts those who are subject to it. Most Burmese are familiar with the four a-gati, the four kinds of corruption. Chanda-gati, corruption induced by desire, is deviation from the right path in pursuit of bribes or for the sake of those one loves. Dosa-gati is taking the wrong path to spite those against whom one bears ill will, and moga-gati is aberration due to ignorance. But perhaps the worst of the four is bhaya-gati, for not only does bhaya, fear, stifle and slowly destroy all sense of right and wrong, it so often lies at the root of the other three kinds of corruption. Just as chanda-gati, when not the result of sheer avarice, can be caused by fear of want or fear of losing the goodwill of those one loves, so fear of being surpassed, humiliated or injured in some way can provide the impetus for ill will. And it would be difficult to dispel ignorance unless there is freedom to pursue the truth unfettered by fear. With so close a relationship between fear and corruption it is little wonder that in any society where fear is rife corruption in all forms becomes deeply entrenched.

President Ilham Aliyev's opening letter to participants of the Third Meeting of the Heads of Anti-Corruption Organizations and Ombudsmen of the Economic Cooperation Organization Member States (6 June 2017) http://www.today.az/print/news/politics/161995.html
Anti-corruption policy

The 1985 Disraeli Lecture (13 November, 1985).

"The Criminality of the State" in American Mercury (March 1939). A similar statement was later made by Jerry Ford

Mobutu explaining the reasons behind his November 1965 coup. Young and Turner, p. 42

Source: The Anarchist Cookbook (1971), Chapter Three: "Natural, Nonlethal, and Lethal Weapons", p. 78.

Letter http://oll.libertyfund.org/index.php?option=com_content&task=view&id=1407&Itemid=283 to Mandell Creighton (5 April 1887), published in Historical Essays and Studies, by John Emerich Edward Dalberg-Acton (1907), edited by John Neville Figgis and Reginald Vere Laurence, Appendix, p. 504; also in Essays on Freedom and Power (1972)
Paraphrased variant: All power tends to corrupt and absolute power corrupts absolutely.
Context: I cannot accept your canon that we are to judge Pope and King unlike other men, with a favorable presumption that they did no wrong. If there is any presumption it is the other way against holders of power, increasing as the power increases. Historic responsibility has to make up for the want of legal responsibility. Power tends to corrupt and absolute power corrupts absolutely. Great men are almost always bad men, even when they exercise influence and not authority: still more when you superadd the tendency or the certainty of corruption by authority. There is no worse heresy than that the office sanctifies the holder of it. That is the point at which the negation of Catholicism and the negation of Liberalism meet and keep high festival, and the end learns to justify the means.