Upon further reading I will change my argument to say that memes are parody.
Parody is very strongly protected while satire is less so but still protected.
https://apps.americanbar.org/litigation/committees/intellectual/roundtables/0506_outline.pdf
they note that:
satire that does not target the original work can be considered fair use if, for instance, there is little possibility that consumers would view the satire as a commercial substitute (§ 107(4)), or if only a small amount of the copyrighted work was used (§ 107(3)).
C
I think a single frame from a movie that has been turned into a meme satisfies both of those conditions.