  Electron-electron interactions generally reduce the low temperature
resistivity due to the screening of the impurity potential by the electron gas.
In the weak-coupling limit, the magnitude of this screening effect is
determined by the thermodynamic compressibility which is proportional to the
inverse screening length. We show that when strong correlations are present,
although the compressibility is reduced, the screening effect is nevertheless
strongly enhanced. This phenomenon is traced to the same non-perturbative
Kondo-like processes that lead to strong mass enhancements, but which are
absent in weak coupling approaches. We predict metallicity to be strongly
stabilized in an intermediate regime where the interactions and the disorder
are of comparable magnitude.
