There is no greater duty than to war on the corrupt and unprincipled boss, and on the corrupt and unprincipled business man
 Theodore Roosevelt, Theodore Roosevelt; an Autobiography (1913). copy citation

Context

“and they delivered malignant judgment on a dead man who, whatever his faults, had in his youth freely risked his life for a great ideal, and who when death was already clutching his breast had spent almost his last breath on behalf of humble and friendless people whom he had served with disinterested loyalty. There is no greater duty than to war on the corrupt and unprincipled boss, and on the corrupt and unprincipled business man; and for the matter of that, on the corrupt and unprincipled labor leader also, and on the corrupt and unprincipled editor, and on any one else who is corrupt and unprincipled. But where the conditions are such, whether in politics or in business, that the great majority of men have behaved in a way which is gradually seen to be improper, but which at one time did not conflict with the generally accepted morality, then the warfare on the system should not include warfare on the men themselves, unless they decline to amend their ways and to dissociate themselves from the system.” source