On the federal level, you have a number of big sources of authority. The most dramatic is probably the Executive Order: the President has sat down at his sweet desk, pulled out The First Pen (ink force one?), and made some sort of Decree. He doesn’t get to make up new laws, but he does wield a lot of power. Hell, with an Executive Order, President Truman almost nationalized the steel industry.
The trial process is fairly straightforward in America; we have an adversarial trial system which is founded on the presumption that the ultimate truth is reached through a vigorous debate. The thinking goes that instead of entrusting the finding of facts to a single neutral investigator, we can just embrace the human tendency to make snap judgments or bring biases with them into their courtroom. It’s easier to trust someone to be biased than neutral, I suppose.
So we set up two parties on opposing sides, to seek the truth through competition. Like most competitions in our society, however, we don’t allow the competitors to employ every vicious trick they can think of. Partly because there are some really effective tricks that lawyers can think of.
In what scientists will doubtlessly (and breathlessly) refer to as Dominic’s Icy Precipitate Postulate of ’09, I postulate the following.