It was quite obvious for regular readers because the day after the election the entire makeup of the subreddit changed.
There could have been some other event that changed the makeup too...
If you say so. I've been glued to that sub for months, and it's still filled with anti-trump messages, pro hillary, pro bernie stories.
I'm not sure what you mean by the entire makeup changed? It seemed that a lot of democrats were upset by the election, but I didn't notice anything that would leave me to believe that shills had left or ever even existed there in the first place.
(disclaimer: i m not american). Well a visit to /r/politics at the time would convince you. Also note how /r/the_donald had like ~250.000 users while /r/hillaryclinton ~30.000 . So it seems most hillary supporters would deflect to /r/politics because they liked what they saw there.
See my other comment in this thread describing it a bit. Also, see this: