The world of Twitter is awash in all sorts of characters, but not all of them are real. Everyone from companies, to politicians, to trolls, to porn advertisers use bots for one purpose or another. If you've been on Twitter for any amount of time, chances are you've run into a few.
According to a study done by Oxford University, bots made a pretty large appearance during the night of the Trump vs. Hillary debate, with the majority of them being pro-Trump accounts.
From the BBC:
http://www.redstate.com/brandon_morse/2016/10/18/high-number-pro-trump-tweets-debates-come-bots-says-new-study/