We show that the energy-level splitting that arises from grain rotation ens
ures that paramagnetic dissipation acts at its maximum rate, i.e., the cond
itions for paramagnetic resonance are automatically fulfilled. We refer to
this process as "resonance relaxation." The differences between the predict
ions of classical Davis-Greenstein relaxation and resonance relaxation are
most pronounced for grains rotating faster than 1 GHz, i.e., in the domain
in which classical paramagnetic relaxation is suppressed. This mechanism ca
n partially align even very small grains, resulting in linearly polarized m
icrowave emission that could interfere with efforts to measure the polariza
tion of the cosmic microwave background.