This isn't specific to politicians. Calling someone a fascist in
public(meaning 10+ witnesses I think) is considered defamation
and, yes, if you cannot prove such claims it can have
consequences.
Note that this does not apply to just any kind of insult as you
say. It's for cases when it's considered harmful for one's
public image, as usual with defamation. I've never heard of a
simple "Idiot!" leading to any consequences. I don't know
why it's "incredibly fascist" to win a defamation case when
someone called you a fascist in the open. Though I do admit that
it's hard to draw a clear line with these things, and there are
arguments for both sides as long as it doesn't steer towards
censorship.
Note that this does not apply to just any kind of insult as you say. It's for cases when it's considered harmful for one's public image, as usual with defamation. I've never heard of a simple "Idiot!" leading to any consequences. I don't know why it's "incredibly fascist" to win a defamation case when someone called you a fascist in the open. Though I do admit that it's hard to draw a clear line with these things, and there are arguments for both sides as long as it doesn't steer towards censorship.