Nearly everyone knows about the Bill of Rights, or maybe a more correct assertion might be: Nearly everyone knows about certain parts of the Bill of Rights.
There is the 2nd Amendment, which enumerates the right of individuals to keep their guns. The 4th Amendment which gives an individual protection from government taking and searching their private property unless there is a good reason (probable cause) and the proper paperwork has been filled out and presented. My personal favorite is the 3rd Amendment, probably because I can't think of one instance where the government has violated it.
The First Amendment is the amendment that gets the most press. Some high school in Texas wants to have a prayer before a graduation ceremony? Some judge in Alabama wants a copy of the 10 Commandments in the courthouse? Sorry, the ACLU might have something to say about that (incorrectly asserting the "separation of church and state" and "establishment of religion" clause in Constitution). Dr. Alan Keyes (yes, the one who got creamed by Obama in their Senate "race") wrote an excellent piece awhile back about it called "On the establishment of religion: What the Constitution really says"
But I digress, here is what the First Amendent says:
Congress shall make no law respecting an establishment of religion,
prohibiting the free exercise thereof; or abridging the
freedom of speech,
or of the press; or the right of the people
peaceably to assemble, and to
petition the Government for a
redress of grievances
There are ALOT of people out there that believe that the Government routinely abuses its power and in the process its citizens. I'm not talking about criminals, or terrorists, or people who are trying to overthrow the government. I'm talking about law-abiding people who live in both the red and blue states. It explains the rise of groups like We the People, and The Free State Project, and political parties like the Libertarians and the Constitutionalists (what I call the Constitution Party). These groups, especially We the People, are active in petitioning the government for a redress of grievances and working within the framework of the Constitution.