“There’s a lot of shock that this president and this administration would roll back a decision on trophy hunting like this,” said Tanya Sanerib, a senior attorney with the Center for Biological Diversity, which fights to protect species threatened with extinction. “But there’s something about elephants that just crosses party lines. They get to people.”

Aides said it was no more complicated than that. The president likes elephants, they said. He did not know about his administration’s decision to lift the trophy ban until learning it from the news media and was annoyed to be criticized for a move he had no part in. So he made his displeasure known in the way he has so many other times this year, through his Twitter feed.