I think you underestimated how much power “executing the law” gives you. And no matter what you believe, it can be immoral to not exercise this power sometimes.

Sure you can educate the populous and hope good people are elected, but you can’t guarantee things always go how you hoped. What if the Congress passes some truly reprehensible law? One you deeply disagree with? e.g. genocide, apartheid, weapons for the oppressor, tax break for the rich, what have you. Would you still hold on to your beliefs and execute the law faithfully? Should you?