“Whether it’s a joke or not is not the question,” said Ghosh. “The question really should be, does this serve to potentially mislead a constituent, even one constituent?”

The danger with tweets like the fake Sanders quotes, said Mike Caulfield, head of the Digital Polarization Initiative for the American Democracy Project, is that a medium like Twitter “atomizes” posts — meaning a user will likely only view one post without context, never seeing the campaign’s claim that it was joking.

Only two candidates — Joe Biden and Elizabeth Warren — have issued official pledges to not use illicit tactics. In June, Biden promised no bots, deep fakes or disinformation. Warren has openly feuded with Facebook over its standards for allowing false statements in political advertising, and she released a policy proposal to crack down on disinformation.