Will Donald Trump benefit the enraged white working class that brought him into the White House? To answer this, one must examine his plans and the desires of congressional Republicans.

One must also consider how these plans might affect the world economy. The conclusion is straightforward: some people will indeed benefit but the white working class will not be among them. Republicans have long stoked rage they do not assuage. Trump has taken this approach in new directions.

Regressive tax cuts

Huge, permanent and regressive tax cuts seem the one certainty. It is something on which Trump and congressional Republicans agree. The revised Trump plan would reduce the top individual income tax rate to 33 per cent and the corporate tax rate to 15 per cent. It would also eliminate the estate tax.

The highest-income taxpayers – 0.1 per cent of the population, those with incomes over $3.7million in 2016 – would receive an average cut of more than 14 per cent of after-tax income. The poorest fifth’s taxes would fall by an average of 0.8 per cent of taxed income. To those who hath, it shall be given.

Trump (much less so the congressional Republicans) plans to increase infrastructure spending. This is desirable, though it would have made even more sense if Republicans had supported such a programme in the midst of the Great Recession. But as noted by Lawrence Summers, former US treasury secretary, the Trump plan relies mainly on private investment.

Experience elsewhere suggests this often leads to exploitation of taxpayers and a failure to put into effect public investments that deliver high social benefits but have limited commercial returns. Large rise in fiscal deficits

The net effect of these plans would be a large rise in fiscal deficits. Calculations by the Tax Policy Center at the Brookings think-tank suggest that by 2020 the deficit would increase by 3 per cent of gross domestic product.

With current forecasts as the baseline and ignoring any additional spending, this would mean a deficit of around 5.5 per cent of GDP in 2020. Cumulatively, the increase in federal debt by 2026 might be 25 per cent of GDP.

Congressional Republicans such as Paul Ryan would surely demand matching cuts in spending. Annual federal outlays are close to 20 per cent of GDP. Spending on health, income support, social security, defence and net interest absorbed 88 per cent of this in 2015.

Elimination of spending on all else (a catastrophic mistake) would merely halve the prospective deficit. In sum, the plan’s logic leads towards either big increases in federal debt relative to GDP or sharp cuts in spending on programmes on which Mr Trump’s supporters depend.

The envisaged rise in US fiscal deficits would, however, be expansionary, even though the concentration of the cuts on the wealthiest would limit this effect. World economy is fragile

Still, a jump in US fiscal deficits would accelerate rises in US short-term interest rates. Trump could hardly complain since he has attacked the Federal Reserve’s low rates. Yet, as Desmond Lachman of the American Enterprise Institute notes, the world economy is fragile. A swift rise in US interest rates might destabilise it.

Furthermore, the combination of fiscal loosening with monetary tightening would mean a stronger dollar and a rising current account deficit in the medium term.

The US would re-emerge as the global buyer of last resort, so helping the world’s structural mercantilists: China, Germany and Japan. A strong dollar and rising external deficits would, as in the early 1980s, increase protectionist pressures – Ronald Reagan’s administration was quite protectionist in its first term.

The decision to launch the Uruguay round of multilateral trade negotiations to liberalise world trade was then the response. This time, however, a strong dollar would reinforce the bias towards protectionism of the Trump administration. But protection against imports would raise the currency’s value further, shifting the adjustment on to unprotected sectors – above all, on to competitive exporters. In all, a strong dollar must weaken the manufacturing Trump seeks to help. Cajole the Fed A likely response would be to cajole the Fed into slowing monetary tightening. Janet Yellen’s term as Fed chairwoman expires in 2018. Her successor could be told that the 4 per cent growth mentioned by Trump has to be attained.

The last time such growth was achieved over a five-year period was before the crash of 2000 – an ominous warning. If the Fed tried to achieve this goal, it might trigger inflation, financial instability or, more likely, both. In all this there seem to be few, if any, gains for Trump’s working-class supporters.

The president-elect has also promised to eliminate Obamacare and most environmental and financial regulations. It is hard to believe any of this would succour the prospects of the working class.

They are more likely to suffer from even worse health cover, a dirtier environment, more predatory behaviour by financial institutions and, at worst, even another financial crisis. Protectionism, too, will fail to help most of his supporters. Many depend on cheap imported goods. Global trade war Many would be badly hurt by the dire results of a tit-for-tat global trade war. Meanwhile, rapidly rising productivity would still ensure a steady fall in the share of manufacturing in US employment, despite protection.

Trump promises a burst of infrastructure spending, regressive tax cuts, protectionism, cuts in federal spending and radical deregulation.

A big rise in infrastructure spending would indeed help construction workers. But little else in these plans would help the working class. Overall, his plans might indeed generate a brief economic surge. But the longer-term consequences are likely to be grim, not least for his angry, but fooled, supporters.

Next time, they might be even angrier. Where that might lead is terrifying.

– Copyright The Financial Times Limited 2016