yep arse works for me....
There are plenty of other ways to insult Trump without doing it by insulting some other group in the process...
And basically anything you call him will indeed be an insult to anybody who identifies as said characteristic!
I wouldn't call him a girl, or an idiot, or gay, or mental....I quite like orange shit-gibbon...although I do know someone who works with gibbons trying to protect their habitat...so I probably wouldn't use it in front of her!