Mr Trotter said the ''odd thing'' had been the city voting strongly for National in 2011 and 2014.
Mr Trotter said National remained dominant nationally, especially in Auckland, because it appealed to those who had a comfortable life, house and job.
However, more people were uneasy about the direction of the country.
''I think a lot of people in that comfortable zone have looked over the parapet and seen just how bad things look down below.''
Mr Trotter believed National leader Bill English would respond to that mood by dropping some of the ''austerity'' measures in social spending.
''I think National is going to have to swallow hard and increase spending.''
The expected coalition agreement with New Zealand First would be the main driver of extra spending.
Mr Trotter believed Winston Peters would offend a ''powerful constellation of forces'' if he turned his back on the party that got 46% of votes.
Mr Peters had railed against right-wing economics for decades, but chose National in 1996.
''In 1996 there was a clear majority for change and the swing vote had been invested in his party, and Winston seemed to be leading the charge for a reversal of what we call new-right policies.''
Mr Peters chose to prop up an unpopular National government in the 1990s.
In contrast, in 2017, the National government was very popular, securing more of the party vote than when it took office in 2008.
''Winston understands the nature of National's support base. He has had very good reason to understand the nature of its fury when it is unleashed against him.''
