If you dislike their politics, so be it - donate to campaigns or personally run against them. Write a letter explaining how you'd like them to vote.. But the amount of absolute crass behavior people allow "because it's the internet" is mind boggling.
It's debatable.
Imminent exhortations of others to break the law should be illegal.
Past that, it's a slippery slope to pre-arresting people for thought crime.
As abhorrent as some of the language is, it seems... dicey... if the US had simply banned gangster rap, NWA, fuck-the-police style music. And it's a tenuous line from threat to actual violence.
Which is why "credible" is usually the standard for charging. I.e. did you make a threat and take actions to realize the threat?