A do-or-die commitment to either party is a primitive tribal reflex. It can't be policy or philosophy. It has been a long time since National or Labour committed to political principle. Under MMP, the two old parties hug the centre and the party that wins the centre wins government.
Labour has also done the Greens no favours. It backed Green nemesis Winston Peters in Northland. Helen Clark chose United, not the Greens, for Government in 2002. In 2005, she chose New Zealand First. With a choice, Labour left the Greens out in the cold twice. The Greens owe Labour nothing.
The Greens also have no leverage as Labour cling-ons. Labour takes their support for granted. The Greens would win more green policy hooking up with National.
A fourth-term John Key would appreciate a sprinkling of Green fairy dust. He would give the Greens a lot for that. Also, the threat of National would see Labour willing to give the Greens more policy concessions and greater power.
The Greens need leverage but right now they haven't got it.
I would think Russel Norman maxed out the vote to the left of Labour at the last election. It still left the Greens beached in Opposition. Even if they had got more votes they still wouldn't have made it.
More Green votes would have catapulted Peters into power.
More votes for the Greens don't translate into Government. Positioning does.
Shaw, ex-PricewaterhouseCoopers, is Green through and through and is targeting middle New Zealand.
He would sit happily with National in return for good Green portfolios and serious policy achievements. Hague is a leftie. He suffers battered Green syndrome and thinks the harder he tries to please Labour, the less they will bash him.
Shaw can win more votes. He can also do something more important: he can put the Greens into power.
Picture the look on Peters' face if the Greens blocked him from Government. I would vote Green 2017 just for that.