Well, understand that things like this are not just happy turns of events ("Wow, celeb x,y,z is on our team! What a win!").

We should consider the premise that Celebrity is a phenomenon that equally dazzles the population of all political stripes. It's really just a difference of which specific celebrities with specific opinions that are elevated, celebrated and followed by any given citizen engaged in the culture wars. That being the case, naturally it is an EXTREMELY effective social engineering tool because of how celebrity easily blinds one's individual use of reason. For most people, they crave celebrity to somehow validate one's own feelings and opinions.

I think the proper response to a tweet like this is to start digging on possible reasons why the social engineers would angle for someone like Rowling to become a current darling of social conservatives? (Similar question should be posed about Dave Chappele a few years ago).

I believe these are strategic plays of culture war co-belligerency but for reasons contrary to those engaged in the culture wars. For example, Rowling is not an individual celebrity she's a proxy for the entire HP empire and ethos, and so what do we really know about the origins, contents, and purposes of the HP project?

I suggest this article as a starting point, without necessarily endorsing every theory. But the deep dive on Rowling's background is something to consider, as well as some of the HP analysis.

http://mileswmathis.com/potter.pdf