Newspoll probably wrong since Morrison became PM; polling has been less accurate at recent elections
As the fallout from the pollsters’ failure in the 2019 federal election continues, the University of Melbourne’s Adrian Beaumont points out in this cross-posting from The Conversation that polls have been becoming less accurate in recent years.
Since Scott Morrison became PM in August 2018, Newspoll has usually been the best pollster for Labor. This was particularly so in late 2018, but these strong polls for Labor should now be questioned. In November 2018, Labor had two 52-48 lead results from Essential and Ipsos, but two Newspoll results the week before and the week after those polls gave Labor a 55-45 lead.
In late 2018, Essential usually gave Labor a lower two party vote than Newspoll, even though Essential’s preferencing method was better for Labor than Newspoll. Essential used last-election preferences, while Newspoll adjusted One Nation’s preferences to 60-40 to the Coalition – from the results, this adjustment was justified.
None of those examples you have listed are wildly off the mark.
Nate Silver summed it up best.
“Still, some of the headlines in the Australian media are idiotic and embarrassing. When polls show a race within a couple of percentage points, nobody — least of all journalists, who are paid to be informed about this stuff — should be shocked when the trailing side wins.”