Despite Hillary's lead, an October surprise could still see Trump win
Donald Trump and Hillary Clinton meet tomorrow for the second presidential debate. While polls indicate Clinton will win November's race, the dynamics could yet get shaken up - potentially by an 'October surprise' - that could potentially still see a Trump victory.
October surprises are key developments, often foreign policy in nature, that come in the final four to five weeks of the election, and with the capacity to reshape the contours of the campaign.
Perhaps the first example came in 1968, when then-President Lyndon Johnson stopped bombing in North Vietnam on Halloween.
The move was widely interpreted as an effort to bolster support from Democratic Party voters for Vice President Hubert Humphrey, who was facing a very tough contest against Republican Richard Nixon. While Nixon ultimately won out, the election result was closer than predicted.
However, October surprises can help parties of the challenger, not just White House incumbents. An example came in 2008, during the administration of George W Bush, when Democrat Barack Obama benefited from the intensification of economic problems in the country.
Following the unexpected bankruptcy of Lehman Brothers in mid-September, the Dow Jones Industrial Average index fell almost 20pc in the first week of October. The declining economic fortunes of the country at that time favoured Obama at the expense of John McCain, whose Republican Party was in power.
It was widely perceived that McCain, a Vietnam war hero, was not the right person to tackle the problems afflicting the country, having said only days earlier that the US economy was "fundamentally sound".
Debate rages, of course, over how impactful October surprises can be. Many, if not most, voters tend to have their minds made up by this late stage of the race, and it is almost impossible to put the result down decisively to a single event or process, given the amount of variables in play in long campaigns.
With most polls still pointing to a Clinton victory, especially since the first debate, political watchers are considering scenarios which might see Trump secure a lead again, and possibly even a win in November.
While such outcomes are dismissed by some Democrats, a Trump victory is not impossible. He has held poll leads previously, and a number of respected academic forecasting models point to a possible victory against Clinton. A good example is the so-called 'time for change' model of Professor Alan Abramovitz, which has successfully predicted the result of presidential elections for almost three decades. The model is based on three key predictive items: the growth rate of real GDP in the second quarter of election year; the incumbent president's approval rating at mid-year; and whether the incumbent party has held the White House for one term or more.
Under this model, the stronger the growth of the US economy in the second quarter of 2016 (which was 1.2pc) and the higher Obama's approval rating in mid-year (which was +6 in the Gallup poll from June 27-July 4), the more favourable the forecast for Clinton.
However, in 2016, the model also includes an estimated reduction in vote share of more than four percentage points for the Democrats, reflecting the fact that it is very difficult for a party to win three consecutive terms. The 2016 model estimates that Trump should be clear favourite to defeat Clinton.
Based on these economic and political fundamentals, therefore, it is far from fanciful that the race could yet turn around in coming weeks, whether an October surprise is the precursor or not. It is also far from clear that Trump is running an effective campaign, which partially reflects his lack of political experience as a media celebrity and businessman.
Taken overall, however, Clinton's lead is far from unassailable as the second debate nears. In what has been a remarkable campaign, there could be a further twist to come which sees Trump regain a lead.
Andrew Hammond is an associate at LSE Ideas (the centre for international affairs, diplomacy and strategy) at the London School of Economics