Twitter won't start by censoring something for the blatant purpose of killing Trump's campaign. They'll start on tweets that are obviously bad, then they censor slightly better ones, then censor ones that are slightly better than that, etc. It's like the frog being placed in water that gets hotter and hotter until it boils.
So they start by censoring conspiracy theories and misinformation, things that nobody defends. Then they gradually censor things that are more and more reputable. The Post is a tabloid, but it's a lot more reputable than conspiracy theorists. The accusation isn't world-shaking and might be false, but it's more important and less likely to be false than conspiracy theories and injecting bleach. We're already at several steps down the road, where Twitter censors things that have problems, but nowhere near as many problems as the things they started the censorship with.
By the time they get around to censoring things that are completely innocuous and have no problems *at all*, it's going to be too late.