  Searches for dark matter scattering off nuclei are typically compared
assuming that the dark matter's spin-independent couplings are identical for
protons and neutrons. This assumption is neither innocuous nor well motivated.
We consider isospin-violating dark matter (IVDM) with one extra parameter, the
ratio of neutron to proton couplings, and include the isotope distribution for
each detector. For a single choice of the coupling ratio, the DAMA and CoGeNT
signals are consistent with each other and with current XENON constraints, and
they unambiguously predict near future signals at XENON and CRESST. We provide
a quark-level realization of IVDM as WIMPless dark matter that is consistent
with all collider and low-energy bounds.
