  A larger than expected forward-backward asymmetry in rapidity is observed in
top quark pairs produced in proton-antiproton collisions at the Tevatron. The
asymmetry is seen in both the top quark distribution $A_{FB}^t$ and in the
distribution of charged leptons $A_{FB}^\ell$ from top quark decay. In this
paper, we study the kinematic and dynamic aspects of the tight relationship of
the two observables arising from the spin correlation between the charged
lepton and the top quark with different polarization states. We also consider
two benchmark new physics models, an axigluon model and a flavor-changing
$W^\prime$ model. These models could explain the values of both $A_{FB}^t$ and
$A_{FB}^\ell$. We emphasize the value of both measurements, and we conclude
that a model which produces more right-handed than left-handed top quarks is
favored by the present data.
