She took a lot of heat in the press last year for not taking a public stand against Trump and endorsing Hillary. You know, "girl power" over "pussy grabber" and all that.
To Swift's credit, she didn't take the bait.
They must be upset that with all of the millions she takes in that she does not sufficiently donate to liberal organizations/candidates.
Consider it a shakedown (like Al Sharpton used to pull). Write “me” a check and “I’ll” go quiet.