In a nutshell: On Friday, President Trump announced on Twitter that he had contracted the coronavirus. Twitter has subsequently placed a ban on tweets that express a desire for Trump's death. Offending users will have their tweets deleted and their accounts placed in a "read only" mode, and repeat offenders will have their accounts suspended.
Twitter has referenced an "Abusive behavior" rule they implemented in April. It explicitly states: "we do not tolerate content that wishes, hopes or expresses a desire for death, serious bodily harm or fatal disease against an individual or group of people."
Twitter's rationale ascribes the rule's importance to the need to "facilitate healthy dialogue on the platform, and [to] empower individuals to express diverse opinions and beliefs." They state that this "abusive behavior may also lead to physical and emotional hardship for those affected."
Twitter told Motherboard that they "won't take enforcement action on every Tweet," which, from a quick peruse of the #Trump page, would be a difficult undertaking. Instead, they're "prioritizing the removal of content when it has a clear call to action that could potentially cause real-world harm."
For example, perhaps don't suggest to Trump that he should inject bleach as a cure. However, slightly vaguer tweets like the one below appear to be permissible.
My thoughts are with the virus at this difficult time--- Watch that Space (@slimtimcann) October 2, 2020
Intriguingly, Facebook isn't enforcing the same rules as Twitter in this case. Although Facebook doesn't generally allow such dark content, they make an exception for public characters, including politicians. As long as there's no threat of violence or personal attack, there's no violation of Facebook's rules. Hence, if you don't tag Trump in whatever insult you'd like to level against him, you won't get deleted.
Trump is presently suffering "mild" symptoms according to his chief of staff, Mark Meadows, while Lawrence Kudlow, the director of the national economic council, has described his case as "very moderate." The president is receiving treatment at the Walter Reed National Military Medical Center.
Photograph by Charles Deluvio