In my opinion, when you elevate an entertainer or athlete etc., to the level where you're influenced by their opinion enough to vote solely on that basis (at least when not independently arriving at the same position through one's own research), then you're too easily manipulated, intellectually lazy and possibly under the control of cabal propaganda.
That said, and again - my opinion - there's a positive take-away even if you're disappointed with her politics (personally, I could not care less).
Ms. Swift is publicly taking a stand against identity politics, more of which is needed in our culture today, in this sense:
By not supporting Mrs. Blackburn, she is educating her fans that there's nothing wrong with supporting another candidate, EVEN THOUGH IT MEANS, AS A WOMAN, YOU'RE NOT SUPPORTING A FELLOW WOMAN!
This is a very enlightened view, and one that will cost her for expressing, as having taken ANY public position would have. In the age of slogans such as 'I'M WITH HER,' any encouragement for people to think and vote independent from party propaganda, should be welcomed.
Perhaps tl;dr …. but wanted to send Ms. Swift my appreciation. In a democracy (I know, really a constitutional republic), after careful independent analysis by the citizens, the candidate with the strongest platform should prevail….and not because of party affiliation or identity politics.