  X-ray polarization should provide new probes of magnetic field geometry and
acceleration physics near the base of blazar jets, but near-future missions
will have limited sensitivity. We thus use existing lower energy data and X-ray
variability measurements in the context of a basic synchro-Compton model to
predict the X-ray polarization level and the probability of detection success
for individual sources, listing the most attractive candidates for an IXPE
campaign. We find that, as expected, several high-peak blazars such as Mrk 421
can be easily measured in 100 ksec exposures. Most low peak sources should only
be accessible to triggered campaigns during bright flares. Surprisingly, a few
intermediate peak sources can have anomalously high X-ray polarization and thus
are attractive targets.
