  Sand, Treu, & Ellis (2002) have measured the central density profile of
cluster MS2137-23 with gravitational lensing and velocity dispersion and
removed the stellar contribution with a reasonable M/L. The resulting dark
matter distribution within r<50 kpc was fitted by a density cusp of r^{-beta}
with beta=0.35. This stands in an apparent contradiction to the CDM prediction
of beta~1, and the disagreement worsens if adiabatic compression of the dark
matter by the infalling baryons is considered. Following El-Zant, Shlosman &
Hoffman (2001), we argue that dynamical friction acting on galaxies moving
within the dark matter background counters the effect of adiabatic compression
by transfering the orbital energy of galaxies to the dark matter, thus heating
up and softening the central density cusp. Using N-body simulations of massive
solid clumps moving in clusters we show that indeed the inner dark matter
distribution flattens (with beta approx 0.35 for a cluster like MS2137-23) when
the galaxies spiral inward. We find as a robust result that while the dark
matter distribution becomes core-like, the overall mass distribution preserves
its cuspy nature, in agreement with X-ray and lensing observations of clusters.
