  In paper III of this series (arXiv:0901.3612) we proposed a scenario of
superconductivity driven by hole "undressing" that involved a complete
redistribution of the occupation of single particle energy levels: the holes
near the top of the band were proposed to all condense to the bottom of the
band. Here we consider a less drastic redistribution involving electrons with a
definite spin chirality and show that it is in fact energetically favored by
the Coulomb exchange matrix element $J$ over the scenario proposed earlier. It
is shown that spin splitting with chiral states reduces the Coulomb repulsion
and hence that the Coulomb repulsion promotes spin splitting. Superconductors
are proposed to possess a spin-split hole `core' at the bottom of the
electronic conduction band in addition to a spin-split Fermi surface. The new
scenario leads naturally to the existence of a spin current in the
superconducting state and is consistent with the Spin Meissner effect and
negative charge expulsion discussed earlier within the theory of hole
superconductivity.
