In the west of Scotland, it's traditionally the irish catholic community who supported the left wing, political party labour, and the protestants who've supported the right wing conservative party.
Over time this changed with protestants becoming left wing, and catholics becoming right wing.
This occured because after world war II, discrimination based on religion (against catholic, and pretty much therefore irish orgin) started to phase out, and combined with catholic schools becoming state run, made it easier for catholics to go to university and therefore receive an equal education to traditional right wing supporters. So now there are rich catholics and poor protestants, giving allegencies in opposite political directions.
What therefore makes someone left wing or right wing is predominantly self interest. Poor people will naturally favour more left wing policies. There are some rich people who are left wing, but usually these are people who can afford such a moralistic stance. It's easy to be moral and help others when you and your peers have got plenty to go round, and when this happens, traditional right wing parties become a little more left wing to gain these sympathy voters.
And in continuation, modern immigrants tend to be left wing and political party labour or more militant left wing, infact almost exclusively so, because they are typically less well off and more likely a subject of discrimination due to their religion, culture, perhaps even race (race - which in itself became a politically incorrect term for obvious reasons after world war 2, see germans), and left wing policies here typically help those in typically unfortunate circumstance.
On that, it makes me wonder if coloured immigrants will eventually blend in over time. It's easy to be of irish origin and catholic and hide this because of how you look. Being a different colour isn't something that can be concealed. It makes me wonder about discrimination based on culture as well as colour (perceived race). That is, culture becomes integrated, but can colour.
Interestingly, there was recently a lot of public resistance to immigrants being given too many chances. Often they got, and still do but to a lesser extent, preferential treatment over people born here, which is interesting because it's a polar opposite to how previous immigration was treated.
I wonder if it encourages a lack of enterprise among incomers, but it's left wing, and it seems it's a mixture of all the quadras except possibly gamma.