Scott Morrison doesn’t talk about the Canberra bubble much anymore.

It was one of his protective shields against unwanted media inquiries, honed with “on-water matters” when he was responsible for border control.

These days Morrison brushes off unwelcome questions with an “Oh, that’s just politics” riposte.

The bubble is still there but now it’s one the prime minister is more than happy to share with some of his former foes in the press gallery.

Critical questioning of Morrison hasn’t disappeared but there is a “we’re all in this together” united front in Canberra, including a few in the national media.

A key issue on which Morrison can be assured of almost universal support is whether states and territories have the right to close their borders to people from other jurisdictions in the Australian federation.

Queensland premier Annastacia Palaszczuk has been a target of Scott Morrison. Photo: AAP.

On one level it’s ironic because Morrison has been – and remains – the champion border closer during the COVID-19 pandemic, having begun by shutting out people from China in late January, followed by Iran in February and South Korea in early March.

The bans extended to the most infectious country, the United States, at the end of the third week of March.

While Morrison was keen to close international borders – decisions proven prudent and based on health advice – he was never keen on individual states taking their own shutdowns.

However, his commentary on borders has always had a political flavour and it was seen again this week when Morrison took aim at Labor’s Mark McGowan in Western Australia and returned to one of his perennial targets, Annastacia Palaszczuk (also ALP) from Queensland.

Palaszczuk’s government laid out a road map for easing COVID lockdown restrictions at the beginning of May, and it was noted and endorsed at a national cabinet meeting later that month.

After this plan came in for parochial political and business criticism – pushed along by some ill-disciplined talk from Palaszczuk – Morrison couldn’t help himself, publicly urging Queensland to open its borders.

When he announced in mid-June what was in that May road map as if it was a fresh decision (and for which he seemed to take some credit), Queensland’s health minister Stephen Miles congratulated the Prime Minister for finally reading the document.

When Palaszczuk last month amended her re-opening to exclude Victoria after the rapid spread of the virus in and around Melbourne, Morrison was hindered in adding to his previous criticism of the Queensland Government because his Liberal colleague in Sydney, Premier Gladys Berejiklian, was also imposing bans on people from the southern state.

Morrison has still found a way to criticise Palaszczuk by suggesting there is no health advice recommending people from the Sydney metropolitan area not be allowed to travel to Queensland, which reflects the latest restriction announced in Brisbane.

This pointed political distinction looked weak when, just as Morrison was making it, two Queensland travellers who had visited a nominated Sydney restaurant hotspot returned to Brisbane, were acknowledged as being infected and had self-isolated.

Morrison has dropped the direct criticism of Palaszczuk, preferring now to lecture the Queensland premier and others on how they handle very difficult issues.

“Whatever decisions premiers are taking, they have to explain them and they have to outline to the public … what the medical evidence is to support those decisions,” Morrison said this week.

“I think that’s the standard that all political leaders should be held to.”

It might come as a surprise to Morrison but all Queenslanders know that Palaszczuk has been acting at every turn on the advice of her chief health officer, Dr Jeannette Young. The Premier and the Doctor remain in lockstep in this current phase of the state’s response to the virus.

Now Morrison is taking aim at WA’s McGowan, who is in court defending his state’s border closures against an action taken by businessman and political hobbyist Clive Palmer.

The Commonwealth, on the decision of federal Attorney-General Christian Porter, has intervened in the Palmer case arguing against WA.

McGowan has pleaded with Morrison to back off from supporting Palmer but the PM and Porter are adamant.

Porter says the intervention has nothing to do with Palmer and the Commonwealth is not “siding” with the businessman – a political operator who spent up to $80 million assisting the Coalition in its campaign against Bill Shorten and Labor in last year’s election.

Clive Palmer is challenging the WA border closure in the Federal Court.

Despite supporting WA’s border closures early in the year, Porter says the current regime, under which all other states and territories are drawn into the restrictions, is a “complete, all-or-nothing approach” which would not and should not stand.

This ignores the fact the Morrison Government has the discretion to stand aside from Palmer’s action.

Most legal observers believe that, on his own, Palmer would almost certainly not succeed in his case, expected to be decided in October.

As it is the Morrison/Porter move looks political, which is the most likely internal rationale.

What the selective actions and rhetoric of Morrison fail to take cognisance of is that the border closures by McGowan and Palaszczuk are not just taken on advice but are overwhelmingly popular in their respective states.

Private and published polls in WA and Queensland show between 75 and 85 per cent of people are in favour of closing the borders to people from other states, particularly Victoria and New South Wales.

Morrison might consider that when he takes a minute to survey the political horizons that await him.