What's next for National after Luxon holds on?

The Prime Minister held on to his leadership yesterday - declaring it was a united caucus that backed him in a leadership vote. But, Christopher Luxon singled out cabinet minister Chris Penk as a detractor - and in the end, it was Chris Penk who let go. That's the end of that for National - but now they must convince voters there's nothing to see here. Political reporter Lauren Crimp reports.