You can request a bulk download from them, but if too many of us do it it's going to swamp them if it's not automated. IF that's the case I'd recommend a few do and then rehost. There are a lot.
I fucked up the last one. Here's the link I received:
https://www.archives.gov/research/jfk/jfkbulkdownload
BAKER
Bulk Download of JFK files from National Archive link
https:// www.archives.gov/research/jfk/jfkbulkdownload