Yes, there is at least some anecdotal evidence: https://www.buzzfeednews.com/article/craigsilverman/how-mace...

> Earlier in the year, some in Veles experimented with left-leaning or pro–Bernie Sanders content, but nothing performed as well on Facebook as Trump content.

https://www.theguardian.com/technology/2016/aug/24/facebook-... https://www.wired.com/2017/02/veles-macedonia-fake-news/