This visit will demonstrate the close links between Australia and the United States. These ties are manifold and contain a few exotic kinks.

One of the more surprising connections has to do with a past Australian politician whose career is of direct relevance to American voters as they move into the 2020 presidential election.

The Australian politician in question is the legendary figure Jack Lang who served two turbulent terms (1925-27, 1930-32) as Labor premier of New South Wales.

He can now be outed as the Donald Trump of his day.

Jack Lang, like Donald Trump after him, marketed himself as a strong leader who was tailor made for an age of disruption. His belligerence gobbled up media attention.

He too was suitably large and solid in appearance. He was known as the "Big Fella".

Lang, like Trump, first attracted local renown as a suburban real estate man. A shrewd auctioneer and spruiker, he was ruthless and became wealthy. From the real estate world he gravitated into local government and then proceeded to state parliament as a Labor MP.

Lang was never a socialist. He was not a trade union apparatchik. He operated, in the shifting sands of the labour movement of his day, as a lone wolf.

Unburdened by ideology, he picked up factional allies as he went along, operating through a series of pragmatic deals.

The entrepreneurial Lang took over the ALP in NSW by teaming up with militant affiliated unions to outflank the Australian Workers Union.

President Trump is in the same mould as Lang. He has forged a transactional alliance with conservative Republicans and evangelical Christians, which has brought him political power.

In both cases the deals are or were not wholly worthless for the duped party. Trump can be counted on to pack the US Supreme Court with nominees favoured by conservatives and evangelicals.

His tax cuts are intended to please right-wing Americans.

Likewise Lang in his first term as NSW premier gratified the Labor base by pushing reform in such areas as child endowment, widows' pensions and workers compensation.

Lang's second term coincided with the Great Depression. Worrying political and economic developments swept the world just as they are doing now.

National policies to combat the Depression in Australia included Trump-like decisions to increase trade protection and a Xi-like willingness to see the currency devalued.

This pressure in Australia to fiddle with market forces was a godsend for a populist like Lang. He stood up for his base in the face of demands from vested interests for our standard of living to be lowered in order to pay off our national debt.

At his height Lang's style was pure Trumpianism. He too was a snarling orator whipping up his audiences at stage managed rallies. There was the same fondness for snappy chants and slogans ("Lang is Right"). His more gullible supporters lived on a diet of fake news and conspiracy theories.

Lang scared middle-class people when he thundered against the moneylenders who were impoverishing the nation but true to his blustering nature he went quietly when the governor of New South Wales removed him from office in 1932.

Lang never became premier again but he remained leader of the Labor Party in NSW and in this capacity continued to produce periodic dust ups in national politics.

In today's renewed age of demagoguery Lang's ultimate relegation to harmlessness is instructive.

Neutering Lang was a two-stage process. The first operation had a left-wing aura. A coalition of rebels in the NSW Labor Party and militant trade unionists took over the party machine and sacked Lang as state party leader just before the Second World War broke out.

A second and far more strategic operation followed but this time it was in a rightwards direction.

A year or so after they removed Lang as state party leader moderates in the NSW party abandoned their former left-wing allies and reunited with Lang's faction.

In 1943 Lang split with the Curtin government in Canberra but his base did not follow him. Labor, in power now both federally and in Sydney, used the spoils of office to peel off his parliamentary lieutenants.

A centrist approach to government at the state level in particular succeeded in keeping most of Lang's grassroots supporters on side.

Labor in wartime Australia had to distance itself from the radical anti-Lang zealots in NSW just as in the US at the moment Democrats need to rein in the left-wing influence of Alexandria Ocasio-Cortez and her congressional allies if Trump is to be voted out in 2020.

Trump will benefit if the Democrats are fixated on identity issues and moral purity.

Democrats need instead to focus on practical measures designed to undercut Trump's appeal to embattled voters in the American heartland.

The focus, well-disposed commentators are indicating, should be on issues such as health care, jobs, and forging a centrist position on immigration.

Moderation is the path to follow.

The rise of Jack Lang and his subsequent neutering is an object lesson in how a reformist party can eventually find a way to steer safely between disruptive populism and left-wing purity.

Australia survived demagoguery in the Lang era. Democrats in the US going into the 2020 election can take heart from what happened here way back then.

This is a powerful connection between our two countries although it is one that President Trump - or our Prime Minister for that matter - would prefer not to be told about when they meet up in Washington.