For 18 months, Donald Trump was amazingly useful to British politicians. Whatever their party, he provided them with the most magnificent means with which to polish their liberal credentials. In January, when the British Parliament spent three hours debating a public petition to ban Trump from entering the country, we learned from Labour’s Rupa Huq that he was ‘racist, homophobic, misogynist’, from the Conservative Marcus Fysh that he was ‘the orange prince of American self-publicity’ and from the SNP’s Gavin Newlands that he was not only ‘racist, sexist and bigoted’, but ‘an idiot’.