[El Gato]

Just not on what it explains. I contend it explains when the right is protected.

When? Nothing in the amendment indicates that the protection only applies at some times. Or did you mean "who"? Well the operative clause says "who". The preamble explains "why", that is: why the right of the people is protected by the Amendment.

[steve-b]

The preamble explains "why", that is: why the right of the people is protected by the Amendment.

Note that the Court has specifically rejected the argument that such a clause is to be considered restrictive. (See the Eldred case, in which the Court ruled that the "to promote the progress of science and the useful arts" clause does not actually limit Congress' power to grant copyright and patent monopolies).