M0nica, the broader Labour movement has affiliated to the palimentery Labour party for over one hundred years. In that, many Leaders of the party respected the support the trade unions gave the Palimentery party and attended their conferences etc and ensured those unions could operate effectively within society.
However the "Blair era" changed all the foregoing in that Blair & Co were only too happy to take the affiliation subscriptions of often poorly paid trade union members, but never once attended any union conference or revoked any section of Maggie Thatcher's many anti-trade union bills.
Therefore, those grassroots members now have gained a full say in the running and policy-making of the Labour party, and I feel that they now see the party as theirs and that will not change even if the party do not win the next general election.
In other words, they say the party is ours, it will stay ours, and if the wider electorate do not like that and do not elect us, too bad, things will still remain the same.