So I don’t know much about ‘dog piling’ or how much there are concerted efforts to harass or alter a social media presence of a candidate. Not only is it possible, but I don’t doubt that it happens, at all.
On the other hand, meme’s going viral because they are funny and/or because they are quite apropos to a situation or event is an organic social phenomenon and should not be censored just because it happens to help or hurt a political candidate.
Let me help you out FRiend. If a bunch of leftists hold up identical signs, and write nearly identical letters to the editor, and all stand together and say "Trump is awful" that is a wholesome, organic, natural outgrowth of American free speech.
By contrast, when more than a few conservatives or Republicans hold up hand made signs expressing the same general idea, or write heartfelt letters to the editor expressing their opinions, or stand together and say something like "Four more years" then that is "dog piling" and somehow becomes a terrible, awful thing that the Russians (or Ukrainians) must be responsible for, and it must be stopped.