All the cases of people being turned away at the border over social media posts that I have seen reported were about illegal work. I am afraid even the CBP agents might not be bored enough to read some rando's political screeds. But it's impossible to tell for sure as your admission is solely the matter for the officer who would be handling your arrival.
What does this link have to do with what I wrote? There is not even the word "border" mentioned in the article. This article talks about canceled visas, not people denied entry at the border.
You think the same government that will kick people out of the country for saying something they don’t agree with will let people in the country for saying something they don’t agree with?