More of a riot in my opinion.
So here's a story from some relatives just outside the Philadelphia city limits from 2020:
PA had a messed up food fight of election rules in 2020 (Dem governor vs Republican legislature) and the rules that were nominally on the books at the time were something to the effect of mail ballots having to be in secrecy envelopes, with the outer envelope signed and dated by the voter. Envelopes without a signature or without a date were technically invalid.
Unless.
The election workers, without peeking inside of course, spotted the error. Then they were allowed to contact the voter and have him come in to "cure" the ballot by placing his mark in the correct spot on the paper.
But see this "cure the ballot" stuff, while legal, was not mandatory. And poll volunteers in heavily blue Philadelphia and Pittsburgh made a point of doing it, while poll volunteers in other parts of the state weren't as active about it.
Now, even though the poll workers ib Philly weren't supposed to peak inside the envelope to look at the votes that needed curing, there was nothing stopping them from looking at the party registration of the ballot caster. In fact, they pretty much had to see it when they checked the mail ballot.
Rumor was, they were a little more enthusiastic about contacting registered Democrats to cure their ballots.
Provably illegal? Certainly not. Kinda fishy? Oh yeah. Fishy in concert with a whole school of fish...all of which was probably still legal...in the sense that the laws were changed to favor broader access over authentication? You bet your ass it was.