I mostly agree with this with the following caveat:
It might not be legal fraud to grab 1,000 ballots, mark your favorite candidate, and have a homeless person sign it with a smiley face
But it is a moral fraud because you've just disenfranchised 1000 voters who actually care about their vote, care about the results, care about their city
If that is what is happening (which seems likely) then it calls into question the very nature of representative democracy. Why do we even have a vote if the vote result isn't determined by individuals but by NGOs who can harvest as many votes as they want using these strategies?
I'll be writing about this for NR, but I will lay the Los Angeles situation out here flatly. Pratt didn't lose because of fraud. Pratt lost because, just like Chicago, it's an 80/20 Democratic city. In fact, he seems to have placed exactly where was in the final polls.
The real scandal is what's legal: with a 100% mail-in system, an endless window for ballot counting and legal mechanisms for unions and organizers to harvest (and later "cure") ballots, California's system is a purpose-built black box designed to fuel paranoia. And for no other purpose than that it allows Democratic intra-party battles to become a test of organizing strength for NGOs and unions.
People are right to be angry about the system. But even the way the votes are being counted now makes perfect (albeit disgusting) sense without recourse to claims of "fraud."