Brexit, in my mind, is mostly an emotional argument by people with misguided notions of "independence". I have yet to see a rational argument for Brexit but quite a few against it that highlight the risks involved.
The Remain campaign is painting the Brexit campaign as an emotional and racist thing, but there are logical arguements which are not being addressed.
Sovereignty.
Further integration.
The proposed EU Army which will undermine NATO.
The undemocratic nature of the EU lawmakers.
The culture of secret negotiations, particularly TTIP.
Immigration/population explosion which has seen rents for the bottom part of society double in real terms in the last decade.
None of the above are being addressed by the Remain campaign, who just point there finger at anyone who argues with them and call them idiots and racists. Hence the middle ground is left to the right wing.
The reality is that plenty of politicians want this but are too afraid to back it in case the vote fails. Again, leaving the middle ground to the right wing.
All in all, the new entries to the EU aren't exactly rich and aren't really raising the averages any, and Britain - as one of only two net contributors to the EU - is supposed to roll over and spunk up more cash to bail out people who are only in a mess because the EMF (read Germany and France) has fucked them over.
But make that an emotional arguement if you want.