I expect most people realised that your JRM4PM was a joke Baggs, but the rest - where you say Rees-Mogg shouldn't be be blamed for his upbringing - wasn't. I don't think he should be "blamed" for his privileged upbringing. What he is responsible for is his voting record which, amongst many other things, shows his absolute willingness to penalise less well of people while making all sorts of concessions to the wealthier sections of society.
I'm not sure what you mean about "personal" decency. There are many relatively recent historical examples of people who treated those close to them -their family, friends and colleagues/valued employees properly but who most definitely didn't extend the same care and compassion to people they perceived to be outside their milieu.
I don't think there should be two separate personalities - one personal and one political. I would imagine that most people's political beliefs, and their values in general, are to a fair extent reflected in their behaviour.