And here’s what the Trumpers are concerned about if he visits the royal family (well, Charles, anyway—not even considering how the yam used to stalk Diana, who was thoroughly creeped out by him)
A senior government source familiar with the discussions said: “Trump’s people are worried about an awkward moment, with Charles saying ‘Why don’t you believe in climate change?’ or ‘Have you read my book?’ They will react quite strongly to that.

“They do not want the president to be put in an awkward position where he’s being lectured. They want horses down the Mall, tea with William and Kate. They want all that pomp and for it to go seamlessly, and one of the risk factors is Charles.

From the Times of London via
wonkette.com