'In the UK, for example, the Public Order Act 1986 says:
"A person who uses threatening, abusive or insulting words or behaviour, or displays any written material which is threatening, abusive or insulting, is guilty of an offence if -
(a) he intends thereby to stir up racial hatred, or
(b) having regard to all the circumstances racial hatred is likely to be stirred up thereby."
"Racial hatred" is hatred against a group of persons "defined by reference to colour, race, nationality (including citizenship) or ethnic or national origins".
Additional acts outlaw hatred incited on grounds of religion or sexual orientation.'
The law that applies to Trump.