  We study the operator description of the gluon spin contribution ($\Gamma$)
to the nucleon's spin as it is measured in deep inelastic processes. $\Gamma$
can be related to the forward matrix element of a local gluon operator in
$A^+=0$ gauge. In quark models the nucleon contains ambient color electric and
magnetic fields. The latter are thought to be responsible for spin splittings
among the light baryons. We show that these fields give rise to a significant
{\it negative\/} contribution to $\Gamma$ at the quark model renormalization
scale, $\mu_0^2$. The non-Abelian character of QCD is responsible for the sign
of $\Gamma$. In a generic non-relativistic quark model $\Gamma_{NQM}=-{8\over
9}{\alpha_{NQM}\over m_q}\langle{1\over r}\rangle$, in the bag model
$\Gamma_{bag}=-.1\alpha_{bag}$. These correspond to $\Gamma_{NQM}\approx -0.7$
and $\Gamma_{bag}\approx -0.4$ at $\alpha_{QCD}\approx 1.0$.
