Probably depends on whether the attacks focus on the chancellor's race or on their policy. Criticising the government's policy is absolutely vital to a democracy. Criticising someone's skin colour is not.
Though if the target is a politician, I'd expect them to prefer to err on the side of allowing it.
We already know the answer: they will claim that attacks on them are racially motivated (regardless of the truth) and shut them down. Plenty of examples of that sort of thing going on today outside of politics.