Google has no problem scraping html pages and getting importance and content topics from inbound links, social media links and the actual text on the page.
The google search "pass a polygraph" gives antipolygraph.org as result number 11.
The google search "polygraph" give antipolygraph.org as result number 188.
And that is a problem. No company with as much influence on the web as Google has should be able to hide behind a phrase such as "it's just the algorithm". "De-rank every web site with the word humuhumunukunukuapua’a" is an algorithm too.
Every ranking should have a very clear reason, and legitimate web sites (yes, this is a judgement call, but a site with a history like this one would qualify) should have access to that reasoning behind their ranking.
It's not delisted, it's just not on the first page as other users also reported and I just verified myself.
With every change of the ranking algorithm there's a bunch of sites going up or down and nobody can tell you the exact reason why - it's easy to just call it censorship but in reality it's probably something else. Like the top comment already explained that your site markup has a bunch of missing information that makes it hard for search engines to properly scrape you.