1. how does the concept of justice affect the law in the united states?

Answers:
As an interested observer (law student) I'd have to say: Not much, except by accident.

Most public laws are about setting community standards and enforcing particular points of view. Occasionally, those laws are based on an enlightened objective sense of what is best for everyone, to ensure which is fairness and equality. That is one definition of justice.

However, more often than not, laws are made because a majority of people believe one way and seek to force everyone else to adhere to their beliefs. This is the classic "Might Makes Right" approach of a partisan democracy. In other words, whoever is in the majority gets to make the rules, regardless of what the minority thinks.

If you happen to be in the majority on any given issue, then the ruling may look like justice to you. But if you are not, then being forced to do something that you don't approve just because you are in the minority doesn't sound like justice to me.

Couple of examples:

Is it justice to be able to hold people indefinitely, without access to an attorney, without charges, and without a trial -- just becomes one official designates that person as a threat? Apparently, it is legal (see Jose Padilla, Gito, etc.) But I don't think it is just.

Or take the recent law sponsored by Senator McCain which outlaws torture. 89 (of 100) Senators voted in favor of that law. To me, prohibiting torture is a good step towards justice. But 10 Senators voted AGAINST that law, saying that torture is OK in some situations. How is that just?