Realistically, this is exactly how they would go about trying to stop Drumpf. Plausible deniability and all that jazz.
In fact, decisions which Facebook makes this election season will impact the result regardless of the intentionality behind those decisions. Even something as mundane as the mix between links and images impacts different candidates disparately.
Realistically, the only way for anyone not to seem like they're going out their way to attack Trump during this election is to completely forget about fact checking, because he lies so repeatedly and shamelessly about things he's already been caught out on: https://www.washingtonpost.com/news/fact-checker/wp/2016/03/...
In fact, decisions which Facebook makes this election season will impact the result regardless of the intentionality behind those decisions. Even something as mundane as the mix between links and images impacts different candidates disparately.