I use the word insidious advisedly as the following meanings apply:
1) intended to entrap or beguile.
2) stealthily treacherous or deceitful.
3) operating or proceeding in an inconspicuous or seemingly harmless way but actually with grave effect.
It is glaringly obvious that this newspaper is using the old tactic of appealing to our sense of belonging and 'loyalty' to our own group whilst demonising anyone who does not belong! Propaganda works because of this, as did the rise of the Nazi party in Germany under the Weimar Republic.
Social Identity Theory shows clearly how we form bonds with others when shown our similarities yet at the same time instantly feel suspicious about anyone who is not considered a member of our 'group'. Experimental research by Sherrif and Tajfel in the 1960's promulgated this theory. Even being randomly allocated different roles in a mock up situation can lead to huge biases and eventual violence against the non-acceptable group e.g Zimbardo's Stamford Prison experiment in 1971. So extreme can our reactions be that using divisions and inequalities as a means of influencing people is indeed insidious!
In evolutionary terms we need to know who we can trust and who we can't. A basic human instinct is therefore being tapped into here. However, what is really happening is just as glaringly obvious. Your attention is being diverted by petty, childish tactics whilst the institutions which form your society get away with stealing from you. WAKE UP! There are as many white English pickpockets and cheats around as any other nationality. Be more wary when you go out - that you can do. What is more difficult to protect yourself against is rife institutional robbery since the laws of this land are heavily biased in favour of corporate greed whilst the police are used as a private army to prevent any protest about the ways in which we are being financialy abused.