Fact checking is things like Republicans claiming that people in a certain town are eating cats and dogs or their are pedophiles in the basement of a certain pizza place. There isn't any need to model and scrutinize data to fact check the majority of nonsense Republicans spout.
Generally speaking, the responsibility of proof falls on party making the claim.
If I claim that you beat your wife, you are not expected to prove your innocence by showing that you don't do it. Proving a negative is difficult if not impossible in some cases. I have to show evidence to back up my claim.
It's a big claim that "immigrants are eating the cats and dogs in specific town in Ohio" (note the plural).
What was readily checked is the source of such a claim (where did Trump get that from?) and what evidence was provided?
The trace back on that stupidity was unsubstantiated rumours triggered from a walked back local area posting and a slew of images that didn't come from the place in question, etc.
