  The paradigm of portal matter represents a well-motivated extension to models
with kinetic mixing/vector portal dark matter. In previous work, we constructed
a simple leptonic portal matter model in which the portal matter fields could
mediate a new physics correction to the anomalous magnetic moment of the muon
consistent with the observed discrepancy between the measured value for this
quantity and the SM prediction. Here, we present a version of this mechanism by
constructing a model with an extended dark gauge sector in which SM and portal
matter fields exist as members of the same dark gauge multiplets, which
provides a natural extension of simple portal matter models. We find a rich
phenomenology in this extended model, including nontrivial novel
characteristics that do not appear in our earlier minimal construction, and
discuss current experimental constraints and future prospects for this model.
We find that a multi-TeV muon collider has excellent prospects for constraining
or measuring the crucial parameters of this model.
