  A model is presented in which the strongest radio-emitting jet outflows are
produced in black hole systems when the accretion is a geometrically thick
($H/R \sim 1$) inflow ({\it e.g.}, ADAF, CDAF) {\em and} if the black hole is
rotating. For galactic black hole candidates, the model naturally accounts for
the observed correlation of jet outflow with the black hole hard emission state
and predicts an association of strong jets with rapid black hole rotation. When
extended to the supermassive case, the model accounts for the highest radio
galaxy and quasar jet powers and provides additional theoretical support for
the ``spin paradigm'', which asserts that radio loud quasars are produced by
Kerr holes and radio quiet ones by Schwarzschild holes. In some cases, the
angular momentum and energy outflow in the jet may be large enough to
significantly alter the structure of the accretion flow from that predicted by
current models.
