  We consider a simple setup with a dark sector containing dark electrons
charged under an abelian $U(1)_D$ gauge symmetry. We show that if the massless
dark photon associated to the $U(1)_D$ is produced during inflation in such a
way as to form a classical dark electric field, then dark electron-positron
pairs are also produced close to the end of inflation via the Schwinger
mechanism. Their mass is larger than the Hubble scale so they are
non-relativistic at production and remain so for the rest of their cosmic
evolution following reheating. They can account for the dark matter abundance
today in scenarios with a high scale of inflation and efficient reheating.This
points to a very heavy mass for the dark electrons of order $10^{14}$ GeV. Even
with a dark gauge coupling comparable to the visible one of electromagnetism,
the dark electrons are so heavy that they do not thermalize with the dark
photons throughout their cosmic history. Assuming negligible kinetic mixing
with the visible $U(1)$ the dark electrons remain decoupled from the Standard
Model thermal bath as well.
