There's certainly been a handful of very overt political troll commentators with talking point narratives which I've noticed on HN in the last few weeks.
Thankfully HN has a better reputation system in place. News website comments have 0 barrier to entry, and Twitter and Reddit are clearly prone to mass bot'ing. It helps that there's access to an API for transparency on those sites but the persona astroterfing ops are getting more advanced tactics like copying random user comments to build up an appearance nearly indistinguishable from a normal user's history at first glance.