The same dynamic occurs at general elections. Governments usually last one term too long, having survived the previous election only because not quite enough voters liked the alternative. Frequently, as happened to Helen Clark, the mood for change reaches critical mass within a year of the election and the Government's last term is a misery for all concerned.
The next election brings a resounding vote for change.
That is what could happen with the flag, especially if the Labour Party positions itself better on the issue. Labour says it is for a change of flag but not yet, or not the way the Government has gone about it, or not if John Key gets the credit.
The last reason seems to be all that matters to Trevor Mallard who keeps damning the whole exercise as Key's quest for a legacy. He greeted the Flag Consideration Panel's selections this week with pretended glee because one of the four designs is so weak he can vote for it knowing it will have no chance against the incumbent.
Labour should shut Mallard up, not just because his resentment of Key is pathetic, nor because his advocacy of a tactical vote is cynical. They should shut him up because it is strategically dumb.
If Labour really would like to update the flag (and I'm sure it would when it gets the chance) the task will be much harder if the present exercise has resulted in an overwhelming endorsement of the status quo.
What Labour should do is decide and declare now that if none of the four alternatives offered this week proves acceptable, the next Labour Government will take up the task.
A promise of that sort would have two effects on National's referendums. It would mean those of us disappointed in all the designs on offer would not need to settle for the least bad. It would also mean that our non-vote could not be taken as contentment with the current flag.
This is a project I think Labour would do better than National. A national flag is not like a corporate brand and not just a banner to wave at sports grounds. It has to serve purposes wider than selling products, supporting a team or even achieving international recognition.
Primarily it has to speak to us, saying something about us that is true but more subtle than the silver fern. The fern and stars don't work together for me and I think professionals agree. Flags have distinct design rules. When OneNews put our four options in front of vexillologists at their conference in Sydney this week, they were politely unimpressed.
The head of Massey University's college of creative arts, Professor Claire Robinson, wrote in the Herald last week: "It was only at the end of the public design process that graphic designers started to engage with it. We are our own worst enemy for leaving things to the last minute and not standing up earlier. Graphic designers thrive on deadlines."
It was the Government's decision that this exercise should be an amateur contest. Labour, I'm sure, would have done it differently, probably with a professional competition and close Maori participation from the outset. A panel of experienced designers could then have refined a proposal for the public.
The result would be more striking than the compromises with the familiar flag we are offered now. People would need time to get used to it before it was put to a vote. It could be run up some official flag poles to see what we think.
We could even have two recognised flags, the old and new, as we did with national anthems for a while. All that is still possible if the best alternative does well this time but not too well.