Labor have obliterated the WA Liberals, reducing them to a predicted two seats.

It is a victory that is unparalleled in its crushing nature and the largest in the state's history, West Australians have never put this much faith in one party anywhere near to this extent before.

The election outcome has seen territory the WA Liberals considered entirely safe during the last election turn red, noteably former Liberal leader Liza Harvey's seat of Scarborough, Shadow treasurer Sean L'Estrange's seat of Churchlands and retiring MP John McGrath's seat of South Perth.

Meanwhile, seats Labor was surprised to win back in 2017 are even more secure, such as the marginal seat of Jandakot which last night had returned Labor's Yaz Mubarakai with a predicted 19 per cent swing on 38 per cent of the vote.

How long can Labor stay on top?

While electorally the win puts Mr McGowan miles ahead of the state's former premiers, it could also point to his future longevity in the top job.

Given the extraordinary number of seats the Liberals would have to win back at the next state election in 2025, Labor will never have a better chance to enjoy lasting success at the ballot box.

History shows it is unusual for a first term WA government to not secure a second term, but politicians on both sides have long recognised the difficulty of securing a third or fourth term.

Voters usually turn on the government of the day long before then.

Mr McGowan does have a fair way to go to secure the longest reign — Sir David Brand was premier for nearly twelve years, winning four three-year terms, as did Phillip Collier — but this victory could see Mr McGowan on track to break more records.

No Labor leader has governed for two full terms since Albert Hawke in the 1950s, something that now beckons for Mr McGowan, if he wants it.

It is a remarkable victory for a man who, during his long five-year reign as Opposition Leader, was questioned by some of his own MPs about his capacity to even be premier with one Labor predecessor labelling Mr McGowan "as exciting as an open grave".

The Premier survived a caucus plot to replace him with Stephen Smith in 2016—despite Mr Smith not even being in parliament at the time—because some of his colleagues did not even think he could win the 2017 election.

But, after unfathomably large victories two elections in a row, Mr McGowan could not have proved those doubters any more wrong.

The unprecedented wave of popularity Mr McGowan has ridden high on following his handling of the COVID-19 pandemic has been emphatically confirmed by the electorate.

But with a significant victory and a clear mandate comes big expectations—and it does not eliminate Western Australia's more complex problems.

McGowan has 'Unfinished business'

The McGowan Government is likely to use the win to forge ahead with unresolved issues from its previous term.

These include the reappointment of former corruption watchdog commissioner John McKechnie, pushing ahead with its political donation reforms and ensuring the Beeliar Wetlands becomes an A-Class conservation reserve.

But complex issues that existed before the election are still there to be managed.

The McGowan Government will need to address issues with the health system, which doctors warn is 'Heading towards crisis point'.

JobKeeper comes to an end soon, which some industries warn could spell devastation for their business, and some are worried about the impacts on the housing market once the COVID-19 rental moratorium ends at the end of the month.

Plus, those in politics rarely need reminding of how quickly the popularity bubble can be burst.

So, while the historic victory is surely to be relished, it may be fleeting as the re-elected McGowan Government turns to the important job at hand.