“But honestly, you know — horrible things do happen, thanks to the imperfection of human nature, but you can forgive the means if the end is a rejuvenated nation that –”
“I can do nothing of the kind! I can never forgive evil and lying and cruel means, and still less can I forgive fanatics that use that for an excuse! [… A] country that tolerates evil means — evil manners, standards of ethics — for a generation, will be so poisoned that it never will have any good end.”

Sinclair Lewis (1885–1951) American novelist, playwright

It Can’t Happen Here, ch. 24 [Phillip and Doremus] (1935)
    (Source)