He's not the first person to make this call, of course. Back in April, the head of the Dairy and Business Owners Association said the same thing.
And I know as much as anyone that the way she conducts herself sometimes - especially in her capacity as Police Minister - she seems to be a million miles removed from what's actually happening out on the streets, and what her police officers are saying.
The arming of police, for example. So many cops say they think they should be carrying guns more regularly. Poto Williams doesn't seem to hear that. Or doesn't want to listen.
When it comes to what's operational and what isn't, she seems to pick and choose the things she pokes her nose into and the things she doesn't.
And then she just does and says stupid things. Like the time we asked her about the Covid vaccination status of police officers who had to track down and arrest someone with Covid who'd escaped a managed isolation facility.
Instead of answering the question, she said we should make a request using the Official Information Act.
They're just a few examples. And because of all these things, I've probably said at some stage too that I think she's a hopeless Police Minister. But is she really at the root of the current crime wave - like Christopher Luxon thinks she is?
That the root cause of rising gang tensions and rising crime stems from Poto Williams being Police Minister?
Do you really think Poto Williams is to blame for gangs taking potshots at each other? Do you really think she's to blame for gang members moving into a neighbourhood near you?
Is Poto Williams really the one to blame for some young people seeing no other option but to follow their fathers and uncles into the gang lifestyle?
According to Christopher Luxon, she is. Because she's not providing the leadership and support frontline police officers need. And because she's the face of the Government's soft-on-crime approach. That's what the National Party leader thinks.
But who's the one banging on day after day, saying the Police and the Government are soft on crime? Who's telling the crims and the gangs out there every day that they'll get away with whatever they want to do, because there are no consequences? That the Government and the Police are soft on crime. Who's telling them that?
It's not the Police Minister. Nor is it the Police Commissioner.
It's politicians like Christopher Luxon who see the misery caused by crime - and the misery that leads people into crime - as their political meal ticket. Just like the cost-of-living crisis. What was it he said at that conference a couple of weeks ago?
"The cost-of-living crisis - that's how we'll win this election."
Well, he may as well just go all out today and say "out-of-control crime - that's another way we can win the election". He may as well say that because he's effectively doing it with these comments today about Poto Williams being the root of the problem when it comes to gangs and crime.
But there is one thing I do agree with him on, and that's the need for the Prime Minister to get someone else to look after the Police portfolio.
Because, as we all know (and it's a bit of a cliche), perception is reality.
And I think, even if Poto Williams was in reality the best Police Minister the country has ever had, the general perception is that she's one of the worst.
One of the worst because she doesn't have the mongrel that I think most of us expect in a Police Minister. Whether that's the right thing to want to see in a Police Minister, I don't know. But we don't get that with Poto Williams.
Like I said earlier, the clumsy way she answers questions - not decisive. For some reason, we expect a Police Minister to be decisive. 'I'm not tolerating that nonsense, we're cracking down on that'. You don't hear that from Poto Williams and so people think she's soft on crime.
Not a good thing if you're the Police Minister. So, in that regard, I agree with Christopher Luxon and I think we do need a new Police Minister - but I don't agree that she is the root of the problem with gang warfare, drive-by shootings and ram raids.
