Well, now that's just not true. None of the amendments in the Bill of Rights are absolute. Not one. They were not intended to be absolute, either, according to the Founders. Every single one has exceptions.
The constitution, as written, is a whitelist of things the government is allowed to do. The bill of rights is a list of examples of things it is not allowed to do. This suggestion that there are exceptions has no basis in the text of either one. I'll never understand how some people can read, "congress shall make no law," "shall not be infringed," "no person shall be deprived of life liberty or property without due process of law," and other similar statements and come up with "this isn't absolute."