  We consider simulations of Wigner crystals interacting with random quenched
disorder in the presence of thermal fluctuations. When quenched disorder is
absent, there is a well defined melting temperature determined by the
proliferation of topological defects, while for zero temperature, there is a
critical quenched disorder strength above which topological defects
proliferate. When both thermal and quenched disorder are present, these effects
compete, and the thermal fluctuations can reduce the effectiveness of the
quenched disorder, leading to a reentrant ordered phase in agreement with the
predictions of Nelson [Phys. Rev. B 27, 2902 (1983)]. The onset of the
reentrant phase can be deduced based on changes in the transport response,
where the reentrant ordering appears as an increase in the mobility or the
occurrence of a depinning transition. We also find that when the system is in
the ordered state and thermally melts, there is an increase in the effective
damping or pinning. This produces a drop in the electron mobility that is
similar to the peak effect phenomenon found in superconducting vortices, where
thermal effects soften the lattice or break down its elasticity, allowing the
particles to better adjust their positions to take full advantage of the
quenched disorder.
