  We generalize the JIMWLK evolution equation to include the small-$x$
evolution of helicity distributions. To derive helicity JIMWLK, we use the
method devised by A.H. Mueller for the usual unpolarized JIMWLK, and apply it
to the helicity evolution equations derived earlier. We obtain a functional
evolution equation for the generalized JIMWLK weight functional. The functional
now is a sum of a helicity-independent term and a helicity-dependent term. The
kernel of the new evolution equation consists of the standard eikonal
leading-order JIMWLK kernel plus new terms containing derivatives with respect
to the sub-eikonal quark and gluon fields. The new kernel we derive can be used
to generate the standard JIMWLK evolution and to construct small-$x$ evolution
equations for flavor-singlet operators made of any number of light-cone Wilson
lines along with one Wilson line containing sub-eikonal helicity-dependent
local operator insertions (a "polarized Wilson line").
