HN also isn't a space that's dedicated to politics, and when topics do come up the crowd seems mostly "free-market, free speech libertarian"-leaning (although you have a small number of Trumpists as well as socialists like me for some balance).

Even if HN were bigger, it wouldn't be worth the attention of PACs and other activists IMO, the HN crowd is not their voter base. For Republicans the tech crowd is too diverse and immigration-friendly, for Democrats... I'd bet a case of beer that many/most of the US people here vote Democrat anyway since the actions of most Republicans run completely against the needs of tech people.