  I give an exact but deconstructed version of the second-order wave-like
equation that encapsulates the hydrodynamic model for plasmonics. Comprising
two first order equations, the deconstruction has potential uses in
understanding or interpreting the hydrodynamic model, since its meaning is not
obscured by approximation. However, as the physical interpretation of the
deconstructed model is difficult, due to the choice of the polarization as the
significant quantity, I also consider a alternate model based on the
polarization current. This alternate model has a clear and direct physical
interpretation.
