Separation would create animosity towards immigrants and non-Christians.  Currently, we already see problems in the UK with extremist groups blaming immigrants and non-Christian religious groups for pretty much everything from unemployment among whites to a lack of patriotism. Completely separating the church and the state could be seen as a move made due to political correctness and/or to try not to offend immigrants or those from non-Christian religious backgrounds.  This would be providing ammunition to extremist groups, as well as inspiring people who do not share these views to sympathise with them. This would be extremely harmful to the groups who are perceived as responsible for this change. [1]  [1] Iannaccone, Laurence R. “Religious extremism: Origins and consequences” Contemporary Jewry. Volume 20. 1996.