Here is another statement which you can characterize as "people who don't agree with me are part of a vast conspiracy."

> Republicans have been making concerted efforts to stack US courts with conservative judges.

Accusing someone of promoting a conspiracy theory is to accuse someone of making creating an unfalsifiable story, which does not seem to be the case in either my example statement or the original post. Specifically, there are no claims that "evidence to the contrary is fabricated" or "lack of key evidence is due to deliberate suppression." Now it may be the case that the author would respond in this way when presented with contrary evidence, or when pressed for some key supporting evidence, but as it stands there is no cause to levy the "mere conspiracy theory" charge at the author.