Toxic behavior happens on every level of society and to every occupation. Being a politician doesn’t automatically make toxic behavior towards you—it was always okay towards you! That’s how the world works.
However, when you become a public figure and especially a political one people may feel more entitled to lash out against you, as you literally hold power over their lives, even if they themselves may disagree with you (as in, voted for someone else or the like.)
Absolutely not, but raising yourself above the line of visibility for public office (or in fact, any kind of fame) more or less automatically comes with its share of negatives.
That doesn't justify the toxic behavior at all, it is just a statement about reality. And the rude tweets are the lowest form of that, at the higher levels it turns into physical assault and sometimes even murder attempts and the occasional actual murder.
Doesn't mean Twitter needs to host it. HN has its own guidelines. I can't come here insulting you. So while it's perfectly fine to say someone can say something, Twitter has every right to decide that it won't host it. Suggesting otherwise is, in many ways, censorship. And I wouldn't want an HN that wasn't allowed to moderate its discussion.
However, when you become a public figure and especially a political one people may feel more entitled to lash out against you, as you literally hold power over their lives, even if they themselves may disagree with you (as in, voted for someone else or the like.)