Social Media as an Inevitably Biased News Source
These algorithms favor the types of articles and followers that you interact most often. Since during the election I most often interacted with a handful of close friends and coworkers who all supported Hillary, I most often saw Hillary-positive articles on my feed, and often sponsored posts from the Hillary campaign, and from her own obviously biased Facebook page.
My parents, on the other hand, interacted most often with articles that were pro-Trump or anti-Hillary. Many of their close friends also in the baby boomer age group have similar views, so I can only assume that their feed is in direct opposition to mine.