Luxon's claim that he wants to wait to see the election result is not credible. Without waiting for any votes to be counted, he has ruled out having an Act Party Finance Minister. He has also ruled out a coalition with Brian Tamaki's Freedoms NZ Party.
The Freedoms NZ Party has had its principal demand, the end of mandates, accepted by Labour. National, too, has supported the lifting of mandates.
Tamaki says he has much in common with Luxon. They are both Christians. Tamaki is a former National voter. He says the National Party used to believe in freedom.
What does the Māori Party have in common with National that causes Luxon to consider that party a possible coalition partner?
Luxon was correct in ruling out a future coalition with the Freedoms NZ Party. Freedoms NZ's embrace of wild conspiracy theories makes that party dangerous.
But the Māori Party also promotes wild theories to claim Māori are discriminated against even when there are obvious explanations, such as the younger age of the Māori population.
Last week was an example. Parliament gathered for a special session to pay tribute to the Queen's 70 years of service. Māori Party co-leader Rawiri Waititi used the occasion to state: "The British Empire and the power of its monarchy was built of stolen whenua, stolen resources and stolen taonga".
The remarks are not just offensive, but a rewriting of history.
Queen Victoria's Government reluctantly agreed to extend British protection to New Zealand in order to end the murderous musket wars. According to the Ministry for Culture and Heritage's website nzhistory.govt.nz, by 1840 inter-tribal wars had killed an estimated 20,000 Māori. "Many more were enslaved or became refugees." This is out of a total population of just 100,000.
Far from stealing whenua, one of Governor Hobson's first actions was to cancel unfair land deals and return thousands of hectares of whenua to Māori.
How can Luxon listen to a speech designed to sow racial discord and not rule out a coalition with Waititi?
When Tariana Turia and Pita Sharples were in Parliament, the Māori Party was led by MPs who were universally respected for their hard work and constructive approach.
Waititi behaves like a shock-jock. He seeks media headlines by making outrageous statements.
All this may all be academic: Waititi has been reported as ruling out a coalition with Act and National, if Act sticks with its current policies.
But in the meantime, the Māori Party has not hidden its radical agenda. It is on their website.
The Māori Party will: "Commit all Māori to the Māori electoral roll by 2023"; establish a Māori Parliament; make Waitangi Tribunal recommendations binding on the Crown; abolish "full and final" settlements; return conservation land to whānau, hapū and iwi Māori; and ensure that private and local government land can be returned to mana whenua.
Forcing Māori into racial electorates is apartheid. Having rival parliaments is unworkable nonsense. Re-opening every Waitangi settlement would create an unending grievance industry. Giving the conservation estate to Māori will not protect the environment. No council park or individual's land is safe if it can be taken for Waitangi settlements.
Does Luxon agree with any of this agenda? The majority of Labour and Green voters do not support the Māori Party programme.
The next election is Luxon's to win. He needs to reject a coalition with the Māori Party and challenge Jacinda Ardern to do the same. It is something Ardern cannot do. She has no route to re-election without the Māori Party - and no chance of winning with the Māori Party.
• Richard Prebble is a former leader of the Act Party and a former member of the Labour Party.