This election is acquiring quite a few back-to-the-future touches.

There's John Howard, in robust campaign mode. One of those he's spruiking for is the embattled Tony Abbott, with a letter to Warringah voters, a video and a planned street walk.

Then there's a prospect that independent Rob Oakeshott might be set for resurrection. Mr Oakeshott, remembered for that 17-minute speech when he (finally) announced he'd support the Gillard government, could strip the Nationals of the northern NSW seat of Cowper.

And bizarrely, there's Clive Palmer, becoming a player to be reckoned with.

Only last June, Mr Morrison said of Mr Palmer's renewed political push that he thought Australians would say "the circus doesn't need another sideshow".

Well, the sideshow's here and the Liberals are grabbing a prize from its spinning wheel, with an in-principle preference deal with Mr Palmer's United Australia Party (still to be formally announced by the UAP on Monday).

Scott Morrison has overlooked Clive Palmer's controversies in preferencing his party ahead of Labor. ( AAP Image: Darren England )

Morrison crunches preference deal numbers

With Mr Morrison, preferences are a matter of cost-versus-benefit.

That assessment led him to declare recently the Liberals would place One Nation behind Labor. Given the exposé of One Nation's cavorting with the US gun lobby, and how vulnerable the Liberals are in Victoria, Mr Morrison needed to make a gesture.

Anyway, the One Nation preference issue is most relevant to the Nationals, and the edict didn't apply to them.

Indeed on Thursday, Nationals' senator Steve Martin announced the Tasmanian Nationals' Senate how-to-vote card will have One Nation third, behind the Liberals (and ahead of Labor) after an agreement between the two parties.

"One Nation is less objectionable than the Labor/Greens cohort," Mr Martin said.

Nationals Senator Steve Martin prefers One Nation to Labor and the Greens. ( ABC News: Nick Haggarty )

All is forgiven

A cost-benefit analysis leads Mr Morrison to turn a blind eye to the times Mr Palmer stymied the Coalition Government when he had the power to do so, let alone his business practices, including leaving his nickel refinery workers in the lurch.

As is his style, Mr Morrison simply throws a blanket over such inconvenient history.

Preference deals are all very well, but if Mr Palmer's comeback takes more votes off the Coalition than from Labor, it's damaging for the Government. They won't all be returned via preferences.

Of course, Pauline Hanson also has a lot to worry about from any Palmer surge.

What are UAP's chances?

The Australia Institute, releasing its latest round of Senate polling in a report out on Friday, notes a "striking rise in support" for the UAP over its last four polls — from 0.8 per cent in August last year to 3.1 per cent earlier this month.

The current figures wouldn't get the UAP a Senate seat, the report says.

"But if the party's vote continues to grow sharply, it will be an outside chance in Queensland and (surprisingly) Victoria."

Victoria sounds far-fetched, but in the Senate polling, the UAP in that state was on 4.7 per cent.

Last week, Newspoll surveys in four marginal seats across the country had the UAP polling an average 8 per cent, and 14 per cent in the Queensland seat of Herbert.

Two things seem clear

With two weeks gone in the campaign, there's a good deal of confusion about the state of play.

The holidays have broken the flow, and while the parties have their data, we're lacking public evidence about whether Labor's 52-48 per cent Newspoll lead of around a fortnight ago has been maintained.

But a couple of points seem clear. First, Mr Morrison so far has more than held his own on the campaign trail; Bill Shorten has underperformed.

Second, the Liberals' relentlessly negative campaign looks dangerous for Labor. This is especially so as Mr Shorten is facing the full weight of News Corp's hostility.

Labor entered the campaign in a good position. Its challenge is to limit the extent to which its initial advantage is eroded by its opponents' scare tactics.

Shorten has more to lose

Although Mr Morrison is battling for the survival of the Government, it can be argued Mr Shorten has more at stake personally.

That sounds counter-intuitive, but think of it this way.

Mr Morrison has been leader well short of a year. The Government has been generally written off. If the Coalition's loss was small, many Liberals would see Mr Morrison as having done a good job.

It would be another matter with a big defeat, but the blame for a relatively narrow one would likely (and rightly) be rammed home less to him, and more to the disgraceful shambles of the whole Coalition outfit.

But a Shorten loss, against the odds and after years of polling in Labor's favour, would see the blame heaped on him (and shadow treasurer Chris Bowen, a driver of much of Labor's ambitious policy).

Mr Shorten would be criticised not just for his campaign — more fundamentally, he'd be condemned for adopting the big target strategy, so open to scare attacks.

And he'd be blamed for being who he is, a leader with an X factor, when X stands for some hard-to-identify (and seemingly impossible to rectify) political gene that makes voters wary of him.

Bill Shorten has been accused of lacking charisma. ( ABC News: Matt Roberts )

For two terms, Mr Shorten's Government enemies and critics on his own side have underestimated him.

The Liberals thought he could be slain at the royal commission into trade unions that Tony Abbott set up.

Malcolm Turnbull did not grasp how tough an opponent he'd be in 2016.

Anthony Albanese was ready for him to stumble at the Super Saturday byelections.

Once again, facing this ultimate test, watchers are wondering whether Mr Shorten has the goods.

Nonetheless, he and others in Labor appear confident of the numbers, even if in the melee it's not just Coalition seats up for change, but some held by Labor and independents too.

Labor is encouraged that health, its signature issue and at the centre of Mr Shorten's first-week campaigning, is coming through strongly in its research, and climate change has been climbing up the issues scale.

Things will soon ramp up

Now the holidays are over, the campaign will ramp up quickly, with a new Newspoll, increasing voter tune-in, and pre-polling beginning on Monday.

Also on Monday, Mr Morrison and Mr Shorten meet in Perth for a debate sponsored by the West Australian newspaper, an encounter where body language might be as revealing as content.

On Friday next week, they'll be at a "people's forum" in Brisbane.

By then, with only a fortnight left, the trajectory of the campaign may be clearer.

Michelle Grattan is a professorial fellow at the University of Canberra and chief political correspondent at The Conversation, where this article first appeared.