On the other hand, I haven't seen a company where the various politics Slack channel didn't devolved to a couple of white guys in an eco chamber trashing anyone who isn't agreeing with their favorite issue of the day. And god forbid you're NOT part of that channel, because then you're the "one person who doesn't care" or some such. Some issues may be fairly one sided, at least at a high level (gender and race equality), others are much more nuanced (gentrification and housing, the school debt crisis) and the discussions are always bordering on needing HR involved to avoid people screaming at each other. Some are extremely subjective but just as heated in Slack (the whole working from home thing).
So how do you handle it? Let people talk about it but ban the slack channels? Ban it altogether? Have HR moderating the discussions? I honestly don't know. Right now it seems like the status quo of "let it happen and hope for the best" is the best of the bad options you have in front of you, but eventually something goes sour and you have to do something. Basecamp's approach is likely missing the mark, but I'd be curious what others are doing.
If your answer is "Nah, we have tons of political discussions at work and its all positives", you're probably not looking very hard.