Toward a Definitive Test of the Cold Dark Matter (CDM) Paradigm It is unclear whether discrepancies between simulated and observationally-inferred galactic dark matter halos indicate a) falsification the CDM hypothesis, or merely b) failure of current simulations to portray what actually happens in a CDM universe. Large uncertainties regarding the influence of 'sub-grid' baryon-physical processes on CDM halo structure inhibit the ability of cosmological simulations to make firm predictions about galactic structure. I will discuss how consideration of the Galactic halo as a closed system with fixed energy budget might enable a test of CDM on galactic scales regardless of details of baryon physics.