If the Sheriff swore an oath to uphold all laws and many laws are manifestly unjust or evil, the sheriff (all law enforcers) has sworn an oath to uphold evil as long as it is legal. (Slavery for example). So then, show me a 'good' sheriff.....or a good Nazi SS Officer.......or a good burglar .....or good car jacker. If your 'job' is immoral because it fosters or enforces evil laws and you've sworn to do your duty upholding all laws, then 'just don't your job' is participating in evil. Again, show me a 'good' sheriff who ONLY enforces the laws he considers in his own mind to be good and just and ignores enforcing the laws he personally believes are unjust or evil.