With separation of power between law enforcement and legislative branches of government, it is indeed the job of the law enforcement officers to enforce laws ev

With separation of power between law enforcement and legislative branches of government, it is indeed the job of the law enforcement officers to enforce laws even they do not agree with. Of course, there is a threshold beyond which anyone in deep moral disagreement with a policy can and should protest in a variety of civil ways (including quitting such law enforcement jobs), and this is a normal part of how the checks-and-balances of power works. But you must acknowledge that there are many who do not fundamentally disagree with the underlying laws, at least not to a magnitude such that they believe it is worth protesting. And as such, we have officers who enforce those laws, who have not (at this time) quit their roles. Therefore, to the extent that one believes this form of government with checks and balances yields more humane results (on average, over time) than one which merges legislative/judiciary/executive power, and to the extent that you acknowledge legitimate moral opinions exist that are different from your own, it definitely can be argued that it's moral to continue enforcing laws you do not personally agree with -- up to a point. The question is, what is the breaking point where a law enforcement officer protests against a horrible law by refusing to enforce it, quits, or otherwise? Take almost any politically divisive issue, and you will find there's not a very easy answer here -- especially because each person will have a slightly different moral opinion on the matter.