As president, it did not take Mr Bolsonaro very long to realise that pension reform had to be his top policy priority.
Not that he has much choice in the matter. The economic reality facing Brazil is sobering.
The public debt stock is rising every year, almost entirely due to the large current deficit in the public pension system.
The debt stock is already close to 80 per cent of GDP, which is nearly twice as high as the average in emerging markets.
The laws of economics are universal: you can only abuse the public finances for so long; eventually a combination of rising interest rates, slower growth and the sheer weight of liabilities push the debt trajectory beyond the point of no return.
Brazil stands at this important threshold today. If parliament fails to fix the pension problem, Brazil will likely face a currency crisis, another decade lost to recession, massive political upheaval and, eventually, sovereign debt default either outright or via rampant inflation.
The good news is that Mr Bolsonaro has a clear political mandate to effect change.
His lack of ties to the discredited political establishment may be his most valuable asset, at least in the eye of voters.
However, this holds little sway in the shell-shocked parliament, and Mr Bolsonaro’s political capital is being depleted by costly coalitions in parliament and a money laundering investigation involving his son.
Economic issues
The other problem is the economy.
Consumers and investors in Brazil are already putting spending decisions on hold pending approval of the pension reform.
Recent economic data has been extraordinarily weak, raising the prospect of a double-dip recession in Brazil this year. If so, the timing could not be worse.
The hesitation of the private sector, although strongly in favour of the pension reform, could ironically undermine the odds of its passage.
Economic weakness discourages parliamentarians from supporting reforms, which inflict pain on significant and vocal segments of the labour force, such as public sector workers.
Brazilians have already started taking to the streets in protest against spending cuts elsewhere in the public sector.
The government is bound by a fiscal rule, which means that cuts in education and other public spending become inevitable unless the pension deficits are reduced.
It follows that the longer it takes to pass the pension reform the worse the economy will get.
Stabilising finances
Still, despite all these challenges, it is likely that parliament will pass the pension reform sometime within the next few months.
A majority of parliamentarians recognise that there is no even remotely palatable alternative.
Mr Bolsonaro’s trade-offs will certainly water down his reform, but even fiscal savings of R700bn, down from the original target of R1.2tn, would still go a long way towards stabilising Brazil’s public finances.