  Quasielastic electron scattering $(e,e')$ from $^{56}$Fe is calculated at
large electron energies (2-4 GeV) and large three momentum transfer (0.5-1.5
GeV/c). We use a relativistic mean-field single particle model for the bound
and continuum nucleon wavefunctions based on the $\sigma-\omega$ model and we
include the effects of electron Coulomb distortion in the calculation. The
calculations are compared to high energy data from SLAC and more recent data
from Jefferson Laboratory, particularly for kinematics where the energy
transfer is less than 500 to 600 MeV and the quasielastic process is expected
to dominate the cross section. The effects of the predicted weakening of the
strong scalar and vector potentials of the $\sigma-\omega$ model at high energy
are investigated. Possible evidence for `longitudinal suppression' or
modifications of nucleon form factors in the medium is considered, but neither
is necessary to explain the quasielastic data for four momentum transfers less
than 1 (GeV/c)$^2$.
