I just finished _Team of Rivals_, an excellent history of Lincoln and the Civil War. Specifically, the political and administrative side of the war, with a lot less focus on the military aspects.
Something that really popped out at me from the book is how often public opinion is in a feedback loop with the law. Both the formal bits and the realist bits.
I think Levine is right when he says that the law is, more-or-less, what the people with tear gas do. But what the people with tear gas can get away with is partly determined by where public opinion is. And even if the laws about restricting police and military actions are often worthless, other laws matter. Like budgets, and procurement rules. Police can't fire tear gas if they can't buy it.
There's no shortcut, but not all is hopeless. Don't give up.