Aftershocks continue to be felt from Suella Braverman’s incendiary speech on immigration. In one of her most controversial remarks, she spoke of ‘an existential challenge for the political and cultural institutions of the West’ and declared that the ‘misguided dogma of multiculturalism’ has allowed people to come to Britain with the aim of ‘undermining the stability and threatening the security of society’. Some may wonder where such thoughts are leading, writes Sean O’Grady