Five weeks out from an election, bottom lines are everywhere. Almost every minor party has one. Some have several.
 
The bottom line is a strange beast. A party leader announces it with a stern face, and it tells voters, 'On this, we will not move.' Then it is released into the campaign dressed up as a binding contract.
 
A minor party might declare that it will not enter government unless a specific tax is established or abolished, a ministry is created or shut down, or a practice forced on everyone or banned.
 
Typically, the major party it is most likely to partner with has already declared the opposite. Both sides then spend the campaign assuring reporters that the other side will come around.
 
Neither side actually comes around. Coming around would spoil the performance. Instead, the bottom line gradually becomes a 'priority', then an 'aspiration'. Its final fate is to become a footnote in a coalition agreement, to be 'explored over the term'.
 
A bottom line is a price tag, and everyone knows prices can be haggled over. The smaller party sets it high to look tough. The larger party attacks it so any later concession looks generous.
 
When the deal is signed, both parties can claim to have held firm. In a sense, both have. Neither ever intended to hold on to anything except power.
 
Informed voters understand the game. They treat parties’ bottom lines like retailers’ claims of final clearances. Interesting, but not worth believing completely.
 
But when both main parties are polling under 30 percent, as they are now, the small fry are no longer so small, and their demands are harder to brush aside. The big parties have noticed. They have responded by borrowing the small parties' trick.
 
Chris Hipkins’ bottom line is that Labour's capital gains tax will be the only new tax under a government he leads. He will be Prime Minister and Barbara Edmonds will be Finance Minister. That disposes of the Opportunity Party’s land tax, the Greens' wealth tax and the latter’s designs on the finance portfolio in one terse statement.
 
Christopher Luxon’s bottom line is that New Zealand will stay in the Paris Agreement, whatever ACT and New Zealand First think about it.
 
In the past, a major party's word settled the matter. This year, it is just another bottom line – terms and conditions apply.