NBC Washington – D.C. mailed a ballot to every registered voter rather than wait for them to request one. The News4 I-Team learned almost 30,000 of those mailed ballots have come back undeliverable. Investigative Reporter Jodie Fleischer reports on what happens to those voters.

Im guessing they matched registered Republican data base hacked by China and were purged.
Possibly the DNC database of dead voters.