The welfare of the people in particular has always been the alibi of tyrants.
When seeking to exploit others, a common rationalization centers on portraying the group as inhuman; unworthy of the rights afforded normal people. When depicted as unfit for compassion and respect, the marginalized faction loses the claim to equal treatment; and becomes vulnerable to abuse. Achieving such a recategorization often depends upon branding them a danger to cherished values. By portraying the targeted group as a threat to the common welfare and a menace to hallowed virtues, it becomes easier to justify vilifying them. Converting conformity into rectitude designates heterodoxy as vice, allowing a righteous indignation towards those who differ and a plausible pretext for exploitation.
Thus, the welfare of the people turns into the Tyrant's alibi for victimization of others, and the suffering inflicted becomes a source pride rather than shame.
