John Legend Now Says Fat Trump Supporters Are Connected to His Music, But ...

John Legend is changing -- or at least elaborating -- his story about that casting call for fat Donald Trump supporters, and he's definitely connected to it ... sorta.

We got John Tuesday at LAX, the day after he shot a music video featuring Black Lives Matter protesters -- which seemed to be related to the story TMZ broke about a casting call for "preferably out of shape" Trump supporters. The listing said it was for a John Legend production.

While John initially said he had nothing to do with that casting ... he's telling a different story here. Turns out the not-so-thin Trump supporters -- shooting on Friday -- WILL be connected to one of his songs. Hmm ...

Still a bit mysterious, but it's clear from his Monday shoot ... John's embracing the whole political thing. He even has a politician's way with words at times.