You might think its because someone yelled "Pepe" during a Clinton rally or just because the meme is especially popular right now. I think its for another reason:

I think its because the /r/the_Donald's long standing policy of banning anyone who doesnt support Trump entirely from their sub. Now that Donald is literally flip-floping multiple times a day on his biggest issue no one can risk making a post about the issues or about Donald. If he flip-flops and your post is still on the front page of the sub you've just been found guilty of wrong-think and its a nice ban for you.

These trolls and cowards can't survive without a safe-space to run to, so being banned is essentially a death sentence. That leaves most of them too afraid to actually talk Trump or even politics anymore, leaving only Pepe, Clinton, and Robert Byrd left