Hacker News has never been an anything-goes site. Tight moderation, considerate rules, and low tolerance for bullshit have made this a great site to talk about interesting technical topics and ideas. Remember that we all abide by the rules of the site, and that this isn't a magic free speech zone. If you want to talk political topics, the Internet has more than enough outlets.
Political discourse is antithetical to rational, intelligent discussion. This is not an opinion; look only to sites that allow political discourse (Slashdot?), or even our own comments to see how quickly rational discussion can devolve into flaming. One of the major selling points when I introduce HN to other people is the _absence_ of political topics or discussion: leaving the politics out just produces better technical content.
Also, please consider the idea that politics are regional and differ between countries. In Canada, where I'm from, many of the US political topics would never come up; many European countries might feel even more strongly. As a Canadian, I find American political musings and arguments even less relevant and noisy. By contrast, technological topics are always interesting to me - I can appreciate these, and I love that there's this corner of the Internet where I can participate in a reasoned, interesting technical community. Please don't ruin it with politics, especially the polarizing American variant.
I appreciate that the site is willing to take this step, and I sincerely hope it can keep this site useful, interesting and level-headed for the future.
From a British perspective, I find most of the political discussion on HN to be useful, although perhaps I just instinctively avoid some topics. There are a lot of global issues which are being discussed, whether that's climate change, transport, tech and data regulation, job automation, money in politics, licensing and intellectual property, electronic surveillance, global trade, etc.
These are all issues which are relevant to the technology community, as big social issues which are targets for innovation, as moral issues which we have to grapple with, or as concrete barriers which directly impinge on us. I'd say having a space for the technology community to discuss these things is a source of a fair amount of the value of this discussion board.
Having said that, political discussion does have to be subsidiary to technology discussion. Once political discussion gets over a certain level, you're just appealing to a general audience and the forum loses its distinctiveness.
So I sympathize with the moderators. You always have to draw a line in the sand, unfortunately attempting a total ban is going to be just as subjective as what goes on at the moment, which is moderators removing or flagging thread-by-thread (presumably to avoid general topics dominating, or to kill off those particular comment threads which have become toxic). I suggest they just keep on muddling through, and we just acknowledge the process is necessary but messy, and cut them some slack.