After Philadephia, logic and numbers back Clinton for the win – but it's not that simple

Logic and the electoral map suggest that Hillary Clinton will be the next president of the United States, yet even six months ago most commentators asserted her Republican opponent would not be Donald Trump.

Clinton’s win in November is by no means a foregone conclusion. The latest polls show Trump pulling ahead in key states such as Pennsylvania, Florida and Ohio, which would probably mean a majority of Electoral College votes.

We need to take seriously the prospect of a Trump presidency, which would seriously undermine the bipartisan insistence that the US alliance is the pivot of Australian foreign policy.

The party convention season, full of tears, anger and showmanship, is not the best time to evaluate the candidates. They will meet face to face in three debates between late September and mid-October, held at university campuses across the US. Presumably these will attract high ratings, if only for the spectacle.

Understandably, the focus this week has been almost totally on the presidency. But it is worth noting that the vast majority of domestic policies touted by the candidates can only be enacted with the support of Congress – and the full House of Representatives and one-third of the Senate also face elections this November.

Neither Trump’s protectionism nor Clinton’s progressive measures in health and education have much chance of being passed by the new Congress. Were Trump elected it is likely the Republicans would also keep control of Congress. But a Republican Congress would be very resistant to many of the policy changes espoused by Trump.

The Bernie Sanders campaign has pushed Clinton to adopt a swathe of progressive domestic policies. She is committed to better health coverage, a higher minimum wage, cutting the costs of college education, introducing some form of maternity leave, and increasing gun controls. Unless a Democratic landslide gives them control of both the House and the Senate she will struggle to achieve much of her program.

There are areas where a president can make significant changes, even against the opposition of Congress. Barack Obama has used his powers in areas such as immigration and environmental regulation that Trump would almost certainly reverse. And while the Senate can block judicial appointments, only a president can nominate members of the Supreme Court.

The court has enormous clout in the American political system, resolving many issues that we would see as the province of legislators. It is the court that defines how far states might limit abortions and gun ownership, has restricted attempts to control campaign financing, and mandated same-sex marriage. The next president could change the balance of the court in ways that will impact on American lives for generations.

When he was elected president, Obama spoke of reaching across the aisle and building bipartisanship, but in practice the Republicans have been largely unanimous in blocking many of his initiatives. The impasse that both Bill Clinton and Obama faced around their budgets is likely to be repeated over the next few years, irrespective of which candidate wins.

Presidents have much greater discretion in foreign policy, and Clinton has a long record of supporting American intervention, both military and through assertions of soft power. Trump has been at times very critical of US overreach, and has consistently argued that America’s allies need to take greater responsibility for themselves.

But Trump’s isolationist instincts are in conflict with his own bellicosity, and his claims that he knows how to deal with Islamic State. Trump also seems quite oblivious to the complexities posed by major issues such as climate change and massive refugee flows. His very unpredictability and inexperience would almost certainly lead to greater global uncertainty and could encourage military aggression by other countries.

Whether Russian intelligence was involved in leaking emails from the Democratic National Committee, Vladimir Putin clearly wants a Trump win, just as he supports Marine Le Pen in France. One might expect this to undermine support for Trump among Republicans, but their capacity to ignore Trump’s jettisoning the last 40 years of Republican policies seems unlimited.

Obama is the first two-term president since Bill Clinton to leave with rising popularity, and Hillary will campaign to maintain his legacy. But he also leaves in the wake of considerable violence and a recognition that even after twice electing a black president, the US is still scarred by the realities of racism.

There will almost certainly be more mass shootings and terrorist attacks between now and the November elections, and how Americans react may ultimately determine the outcome of the elections. Trump presents himself as the candidate of patriotic Americans, angry and fearful as their country changes around them.

Increasingly, the election turns on whether most Americans share his picture of a country in decline, facing increasing threats, or are willing to endorse Obama’s faith in Clinton’s ability to lead.