Re "democracy in the Labour Party", whether a Blair 'sofa' government, the Labour policy one-size-fits-all policies for each UK country, or a Miliband Manifesto many Labour MP's said after the voters rejection 'I knew it sucked but felt the need to keep quiet' - I'd suggest Labour Leaders aren't internally really that big on 'tents' and the 'd' word.
With YC Labour would get a 'two-fer' as hubby EB would come with, and he's influence would lean towards a tax on anything above £25k, whether solid or moved - a big yay for the left.
I can remember saying a similar thing re Tory MP's up Farage's rear end, but it was only one policy, the EU, splitting the party for decades.
Labour needs both wings to co-exist as will widen your electoral appeal over numerous policies, so it is a question of balance, something the far left has never understood but bit their tongues under a Blair's Labour, never below a 120 seat Westminster majority - as that 'power' could increase the size/cost/salaries of the public sector, unchallenged.
These are clearly different times, socialism needs a near full cheque book, but the account is empty and then some, so going forward 'balance' has to be the order of the day for the Labour Party.
The last thing you want is an uncivil war. IMO