It seems like a rarity for Americans to spend any effort thinking about what they believe. The lack of rigor is apparent in the simplest terms that infiltrate our political vocabulary. Any American can give you an example of his "rights" but can offer no definition of a right, or an articulate explanation for how it is derived.
As a short term assistant professor of American Politics, I lived the mantra of most rookie profs -- to stay one day ahead of the class. I also discovered the truism that one of the easiest ways to understand a subject is to be forced to teach it. Having to explain Locke to 19 year olds was humbling -- but eye opening as well.
A second order effect to being forced into a nominal understanding of Locke led me to significant thought about why I believe as I do. Convenient for the lazy and somewhat uncommitted, I was able to crib from the intellectual bedrock of the Constitution. For the first time I was able to mentally grasp the distinction between liberty and rights.
Liberty is inherently an absence of constraint -- you do what you want, when you want...and devil take the hindmost. It is a condition enjoyed by all creatures from plankton to homo sapiens. The issue with this natural liberty is that it overlaps, and we come into conflict over things and places (property) -- when all have equal claim to everything, violence ensues. In a civil society, people sacrifice some portion of their natural liberty to a collective body politic in exchange for security -- specifically to settle disputes over property, and protect their lives (a form of property) -- both from local violence and outside threats. The remainder of this freedom is considered civil liberty. Relatively simple and straightforward.
The concept of "rights" stems from the idea that the constraints on natural liberty are limited -- and some areas are beyond the powers of government to infringe. In addition, these constraining laws must apply equally to all. Spelled out in the first ten amendments, these limits are complex and subject to interpretation, but the concept is clear.
Laws are the means by which government implements its authorized constraints on liberty. Despite the protestations of the ACLU and libertarians, the rub rests not so much in government infringing our rights, but in people claiming "rights" which are nothing of the sort. More to follow on this.