The problems New Zealand Labour has are not unique. Throughout the democratic world, parties of the centre-left are struggling to maintain their relevance and win elections.
Labour started out representing the working class in a class-based society. But today we find a party that is a loose coalition of a wide range of progressive forces that does not always find it easy to put forward a coherent programme.
Most significant is the divide between the traditional base and educated professionals that has become increasingly obvious following the deregulation of the economy in the 1980s.
The argument (correctly) was that New Zealand could no longer be a small, isolated, highly regulated economy and hope to prosper. Rather, it needed to be an open, trading nation in a globalising world.
Globalisation, however, has turned out to be a mixed bag. On the one hand it increased New Zealand's wealth. On the other hand it has seen the rich get richer, the middle stand still and the poor get poorer.
In countries like the United States and Britain, globalisation is being rejected by an increasing number of people who are tired of waiting for their share of prosperity. While mainstream parties have wondered what to do, a particularly worrying version of nationalism has arisen and is attracting support.
Centre-left parties have not found this new political terrain easy to negotiate because their vote is dividing between those hurt by globalisation and those who have, or hope to have, gained.
Former British Prime Minister Tony Blair, if it is okay to mention him in polite centre-left company, has rightly seen this as a shift away from the class-based politics of early Labour to the division between an "open", or internationalist, and "closed", or nationalist, view of the future.
It is this new divide that has to be addressed by New Zealand Labour and all other social democratic parties if they are to have a future in government.
The way forward is not that difficult to discern and I think Labour is working out what to do. The problem with globalisation is that governments took it to mean they had to accept they could do nothing but make their countries safe for the market. This was and is nonsense. Governments can and should still be active stewards of their economies.
They should also be putting great energy into lifting the capability of every individual and community to thrive in the demanding world that globalisation brings.
This world is far from the one in which Labour began its 100-year journey. Age-old questions like jobs still dominate the agenda, but, as Grant Robertson has pointed out, we are now talking about a future where most of the jobs people will be doing have not been thought of yet.
How do we prepare for this future and many other challenges like climate change, population growth, shifts in cultural preferences and conflict?
To be able to make a difference Labour is going to need a sensible and fair taxation system. Globalisation gives most to those who can participate in the global economy and least to those who can't.
This may prove to be the biggest challenge because it is a moral question. Are we willing to contribute part of our resources to build a future that we can all share in or not? Saying "no" is a recipe for the likes of Donald Trump to succeed. Saying "yes" gives Labour and the world's other social democratic parties a way forward.
Reaching 100 years of age is a great achievement for a political party. But there is no time to rest. The world today is an insecure place and the Labour Party of the 21st century has a secure future to build.
Happy birthday Labour and many happy returns.
