You're right that HN should be a place for intellectual curiosity and substantive comments. But here's what I've seen in the past year:
* Flagrantly allow anti-prop-8 posts and submissions to assist in the smearing of Brendan Eich.
* Flagrantly allow pro-clinton posts and link submissions to thrive on HN.
* Never step-in to stop downvoting brigades on pro-conservative/libertarian/tea party posts.
* After unpopular (with silicon valley) president is elected, ban political conversations on the site.
I won't call you biased, because you've been a damn good mod, but this is probably your worst decision, because it looks like sour-grapes-in-retrospect.
Perhaps you're doing it because the pro-clinton camp is actually becoming too toxic to tolerate. Perhaps you're doing it to avoid the 4chan brigade from promoting Trump. Either way, this is a site full of people skilled at reading between the lines, and, correct or not, this action doesn't look like a way of promoting reasonable discussion.
This is one of those unintended consequences that gobsmack me any time we try out some new idea here. I'm sure anyone who deals with large internet communities has the same experience. The funny thing is that it's always obvious that it was bound to come up, in retrospect—just never beforehand. It's like the unveiling of the murderer in an Agatha Christie novel: hidden in plain view every time.
I don't know if I can respond in a way that satisfies you, but let me try. First, Clinton and Trump stories are equally penalized on HN. Second, it always seems like HN is biased against whatever views you personally hold, not because it is, but because the community is divided and we're biased to notice the things we dislike, and that offend us, more than the ones that don't. Your use of the word "flagrantly" is an instance of this. Why do the things you listed seem flagrant while others do not? Because they're mirroring your own preferences. (See https://news.ycombinator.com/item?id=13083111 and https://hn.algolia.com/?sort=byDate&prefix&page=0&dateRange=... for more on this if you want.)
I guarantee you that the people who feel oppositely to you about X, Y, Z issues feel like their side is flagrantly the underdog in the same fights. This is one of the dynamics behind why political fights are so toxic to begin with.
> Either way, this is a site full of people skilled at reading between the lines
Read my lines, please! Just don't imagine lines, then imagine subtexts between them, and then read the imaginary subtext. Instead, ask. We're happy to explain what's going on—what's actually, really going on, as best we understand it.