I haven't really been around long enough to see a trend one way or the other, but I did have a vague sense of something weird afoot, as I myself did have the experience for a time of several articles being amongst the "chosen for distribution" and then whoosh. Gone. Nada.
I also around that time noticed that while the chosen "politics" articles in general used to be chock full of topical, entertaining and interesting stuff, it also all of sudden changed very dramatically so that everything listed looked like Greek to me, and I looked down the list and saw one after another article of esoteric pseudointellectual pompous emphatically uninteresting drivel (that is, everything other than what was in Politically Speaking, which always remained entertaining) headlined with overblown titles that made me go "WTF? Is that in English?" I shrugged my shoulders, thought to myself that maybe some of the Medium curators had gone on vacation, and some grad school intern with delusions of grandeur had taken over the curation for a while and had promptly steered the politics section into the ditch. Things have improved recently a little, though.
I would add that the single highest total of views I ever got for an article (over 700) was one that I did put "Trump" in the title. Take from that what you will. It was certainly not my best writing, but I happily took the cash.
So, to summarize my rambling thoughts here: I think there was just a glitch in the Matrix here, less by nefarious design and more from just the rampant ineptitude the pervades all aspects of our society, including Taco Bell where EVERY time I go through the drive-through window, I then get home and find an item missing from my order! LOL Just rampant ineptitude I think, more than some concerted "silence the politics" plot.