  We show that a quasi-spherical (QS) hot accretion flow is expected to operate
in all SMBHs, with its rate being capped at dot m_QS,max~0.001 (M/1E8Msun) in
units of the Eddington rate. It is then proposed that AGN jet power is
proportional to the product of the hot accretion rate and a SMBH spin-dependent
efficiency for energy extraction in the form of jets. Predictions from this
model include (1) while radio jets should emerge from all SMBHs, the maximum
jet power goes with SMBH mass approximately as 1E43.6(M/1E8Msun)^{2}erg/s, (2)
even although there are two separate underlying populations of radio-quiet (RQ)
and radio-loud (RL) AGNs, any bimodality in the observed AGN radio loudness
distribution is likely due to a selection effect, such as some imposed optical
magnitude limits, (3) the RL fraction of quasars is expected to decrease with
redshift in the cold dark matter model, (4) host galaxies of RQ and RL quasars
should be drawn from the same underlying elliptical galaxy population, although
RL quasars may have SMBHs that are somewhat more massive than their RQ
counterparts and RL quasars may reside predominantly in core elliptical
galaxies, (5) RL low-luminosity AGNs and LINERs may represent the long,
declining "trailing" phase following the initial, more luminous AGN phase, (6)
a broad anti-correlation between radio- loudness and disk accretion rate is
expected, (7) RL AGNs may be expected to be more abundant in Type Ia supernovae
than RQ AGNs, (8) among RL AGNs a correlation between radio power and
clustering strength is predicted, and (9) RQ and RL AGNs should have, on
average, similar IR-optical-UV properties. ~
