Cui bono?
Trump? Cheyenne Hunt is a Dem/Prog political operative. She probably has a hard time saying his name without an expletive. Not that Trump would mind Swillwell crashing and burning due to zipper control issues.
Katie Porter or Tom Steyer? Not impossible, and Porter seems to be a b#$%h-boss misandrist, but ...
Cheyenne Hunt? Hunt has said that she's doing this simply to expose Swillwell for what he is. That may be, though even if Swillwell is all she says he is and worse, I do not think the CA Dem Party will be thrilled with her taking out their trash.