We trust them to answer to SCOTUS, who we in turn trust to interpret the constitution that a majority of us have agreed to keep. Basically a group of people whose entire job is to interpret the actions in terms of law, constitution, and human rights - a marrying of theories on social contract, natural rights, and separation of powers that we've seen emulated (and improved upon) across the free world :)

Overall, I particularly enjoy this system over one that is accountable to a single entity.

They can be overruled by higher courts, and in some localities they’re forced to run for election.