Every supporter of the New Zealand First Party ought to be embarrassed by the "waka jumping" bill. No respectable political party in a democracy needs a law to keep its elected legislators loyal to it.
Labour and the Greens ought to be embarrassed too that they are obliged to support their governing partner on this bill. Green Party members, to their credit, have made their distaste for it very clear before and during their annual conference at the weekend.
Labour and the Greens are real political parties. That is, they are organisations of like-minded people who can channel their values and views into a coherent political programme to put to a public vote. They choose their candidates for Parliament through internal votes that produce competent and usually reliable MPs.
New Zealand First is different, as it has effectively declared with this bill. It cannot rely on its MPs to remain loyal to the party that put them in Parliament and needs a law that will allow its caucus to expel a member from Parliament who will not go along with something the party intends to do.
Labour and National have both had MPs who "crossed the floor" on rare occasions and though it can bring down governments, neither has felt the need of a law to prevent it. They are parties in the Westminster tradition which values the ultimate right of elected representatives to act on their personal sense of what is right and what is in the nation's interests.