  We propose a bipolar jet model for supernova polarization. Light from the
main component of the supernova (which we call the bulk supernova for short)
scatters off electrons in the jets and is polarized: this polarized light is
added to the direct emission from the bulk supernova and causes the overall
supernova emission to be polarized. The motivation for the bipolar jet model is
to resolve the potential paradox set by an analysis which suggests strong
spherical symmetry for Type Ib supernovae and the expectation that Type Ib
supernovae should be highly polarized in the continuum up to perhaps about 4 %.
For the model we have derived simple, non-relativistic, approximate analytic
formulae for relative amount of scattered flux and polarization. The
polarization formula qualitatively reproduces two main features observed for at
least some supernovae: (1) the rise to a polarization maximum and then decline
with time; (2) the inverted P Cygni polarization profiles of lines. The model
is strictly axisymmetric and predicts a constant position angle of intrinsic
polarization. Since position angle variation of intrinsic polarization is
observed, the model cannot account for all the polarization of all supernovae.
