The judgment call we have to make is whether he actually means the outlandish things he said - mostly flippantly, and in vague terms - and whether White House duties will compel him to retreat even if he did.

Washington's permanent government and the 'K' street lobbyists of corporate America have a way of co-opting US leaders. It is my tentative working premise that Mr Trump is not a new Mussolini and that he will ultimately trim his excesses. Call it a 'soft Trump' if you like, though this too entails its own political risks.

If so, an entirely different economic picture takes shape. His manifesto amounts to a massive fiscal stimulus, with tax cuts across the board, a $1 trillion blitz on infrastructure, and an imperial navy of 350 combat ships.

It is a replay of Reaganomics in the early 1980s, a form of turbo-charged Keynesian reflation, and damn the deficit. It promises a pro-cyclical economic boom, so long as Mr Trump quietly drops his threat of 35pc tariffs against Mexico and 45pc against China.

Mr Trump enjoys the huge advantage of Republican control over the House and Senate. This averts the paralysing gridlock and obstructionism that surely awaited Hillary Clinton had she won. He can overcome the ideology of austerity in a way that she could never hope to do.

There will be friction but House Republicans will hardly resist his plan to cut corporation tax from 35pc to 15pc, or to cut income tax from 39.6pc to 33pc for the rich, to 25pc for middle earners, to 12pc for those below $54,000, and to zero for those under $29,000.

Nor are they likely to block his call for national reconstruction on bridges, tunnels, telecommunications, cyber security, water systems, pipelines and the electric grid, all built with "American steel" and supposedly modeled on Eisenhower's highway expansion in the 1950s.

You might equally say it looks more like Roosevelt's New Deal, even if funded partially by private money and run on a fee-earning basis. Infrastructure spending of this kind is what Left-leaning economists such Larry Summers and Paul Krugman have been calling for all along.

It starts to plug the $3.6 trillion backlog of projects identified by the American Society of Civil Engineers. It address one cause of sliding US productivity growth. It soaks up the corporate cash hoard, helping to bring investment back into alignment with savings.

The budget deficit would probably balloon by at least $450bn - or 2.4pc of GDP - even after offsetting a hiring freeze for public employees. That is potent money.

Mr Trump's tax cuts for the rich are not to everybody's taste. Yet in broad macro-economic terms, this fiscal rebalancing is what Keynesian and monetarist doctors ordered. It becomes easier for the US to escape the 'Wicksellian' trap of a negative natural rate of interest, and therefore to escape clammy embrace of quantitative easing.

Fiscal expansion allows the Federal Reserve to raise interest rates faster, ceteris paribus. Vice-chairman Stanley Fischer has even put a figure on it, suggesting that every one percentage point of GDP in fiscal loosening implies rate rises of 50 basis points.

Trumpanomics shifts the structure of US and global credit, and exchange rates. It was the same regime of "loose fiscal/tight money" that catapulted the dollar sky high in the early 1980s, with dramatic global consequences. 

David Fuller's view

We should recognise that Trump the campaigner is not the same as Trump the President-elect.  The transition was evident from his first, gracious speech a few hours after winning the election.  It continued with his comments following an initial meeting with President Obama today: “Mr. President, it was a great honor being with you, and I look forward to being with you many more times.”

From the moment Trump entered the Republican Primaries he was outspoken, brash and often vulgar.  He knew how to get media attention and it worked.  His often outrageous or bizarre statements dominated news coverage.  Established Republican candidates in the ring became invisible, causing them to lose support and eventually drop out.  Trump used a similar approach against Clinton and remained the focal point of press attention. 

Few pundits took him seriously but Trump was smart enough to do the seemingly impossible, surprising us all.  He galvanised white, mostly working class voters who formed his base.  He also attracted just enough support from diverse groups including Hispanic, Afro-American, and Asian minorities.  Additionally, sufficient business personnel and Wall Street executives were drawn to Trump by promises of fiscal stimulus, less regulation and lower taxes.  These were beyond the reach of that other rich but more traditional Republican, Mitt Romney, although he was also up against tougher opposition.

Trump has previously advocated unpredictability as a negotiating tactic.  As President-elect with Republican control of Congress, he has little further need to harass domestic opposition.  Instead, it looks like he will now be conciliatory, calming opposition and preparing the country for the biggest period of fiscal spending in modern history. 

He will start with a broad program of infrastructure spending, which the USA certainly needs, and everyone from Bernie Sanders to Larry Summers has long advocated. This will provide more fulltime jobs for many blue collar who felt left behind.

Across the board tax cuts will win further support from all hard working citizens.  The projected 15% corporate tax rate will bring many billions of Dollars, currently parked overseas, back into the USA, further strengthening the economy.

Trump will lower corporate regulations, particularly for banks.  This will obviously help the banking sector, as will higher interest rates.  The eventual risk of lower regulations for banks, as we have seen too often before, is speculative excesses which rock not only the banking sector but the US and even the global economy as well. 

Trump’s campaign slogan: Make America Great Again, is now an official government website.  This next and slightly more controversial programme will include a massive increase in military spending, particularly for the US Navy and Marine Corps (see following article).    

All these tax cuts and fiscal spending programmes will provide a massive boost for the US economy, increasing the budget deficit in the process.  The US stock market will be supported by these measures over the medium term, despite today’s generous valuations. 

Eventual danger signs to watch for will be a significant upside breakout by the US Dollar Index, another strong surge in US 10-Yr Government Bond yields, CPI inflation above 3%, and at least two more interest rate hikes, in line with the ‘Three Steps and a Stumble’ rule.