The remain proposition goes well beyond attachment to EU membership

"The remain proposition goes well beyond attachment to EU membership: it is driven by revulsion at the nativist spirit of Brexit’s marauding generals – Nigel Farage, Boris Johnson, Jacob Rees-Mogg – and shock that they have hijacked Britain’s political identity. But that dismay is not exclusive to Labour."

Rafael Behr writes badly in The Guardian, but he touches on something that interest me very much. Enthusiasm, visceral enthusiasm, for Remain is about more than economics and I am not sure what.  Can anyone explain please? 

Neither Messrs Rees Mogg nor Johnson are nativists and I don't understand what is objectionable about nativism, though it's a silly American term, very out of context in the Old World. And even if some people do find it objectionable why should they find it very objectionable? 

I don't believe there are any 'Little Englanders', that's just a literary device, but in any case why are they spoken of with loathing and contempt?

There are deep emotions here. Patriotism is always a very strong emotion, the strongest there is in politics, but what feeds the intense emotional pull towards international organisations? More and more, patriotism is considered suspect in Great Britain (not in Northern Ireland).