10 days from a historic US election, the latest polling data suggests the presidential race is tightening once again between Donald Trump and Hillary Clinton.

Trump has narrowed [Democratic nominee Hillary] Clinton’s lead in the popular vote to roughly 6 percentage points from 7 points a week ago,” though Ms Clinton remains the favourite of forecasters.

The tightening contest comes as American voters appear to shrug off the lascivious comments of Mr Trump caught on tape in 2005 and a slew of sexual assault allegations, while Ms Clinton is struggling to contend with a spate of emails published by WikiLeaks that have reinforced suspicions of financial impropriety at the Clinton Foundation, a $2bn non-for-profit corporation.

David Nakamura, a White House correspondent for The Washington Post, suggested that the reason why neither candidate has been able to pull away decisively in the polls is a toxic political climate: “Clinton’s long history in politics has worn away her approval ratings and made her and her husband polarising to a large segment of the public.

Mr Trump’s supporters are vocal and voluble about their reasons for supporting him. Ally — a native New Yorker who supports the Republican nominee and requested that only her first name be used — was blunt: “Look, I’m Republican. I could never vote for her,” referring to Ms Clinton.

She added: “The country is broken and it needs a non-politician to fix it. Trump is real. Look at her. Look at how corrupt she is.”

The fervent support for Mr Trump and the steady drip of politically damaging news for the Clinton campaign has some questioning whether, despite Ms Clinton’s healthy, consistent lead in the national polls, the election result is a foregone conclusion.

According to Richard Leiby, a senior editor at the Post: “I grew up in the Pennsylvania coal and hunting country — and these Trump people are my people, too. I get their anger. I get why they want Trump.”

He added: “Trump’s clear appeal is to the disenfranchised working class who haven’t seen an actual rise in income in 40 years. These voters revile the Washington political establishment as much as the limousine liberals on the East Coast revile Trump.”

The combination of a country split down the middle politically; an unusually large number of as-yet-undecided voters or those supporting third-party candidates; and two historically disliked, unpopular candidates has veteran journalists like Mr Leiby cautious: “Can we trust polling in key states like Pennsylvania and Ohio, showing that Trump is already locked out of the White House because of an impending electoral college defeat? The polls are no doubt pretty accurate at this point, but not fail-safe. And when people reach the polling station itself, all bets are off.”

However, the Electoral College — a group of 538 electors nominated from individual states on the basis of a state’s Congressional and Senate representation — is a winner-take-all system at the state level and poses a formidable challenge for Mr Trump.

While 270 votes are needed for victory by either candidate, state-level polling indicates Mr Trump has less than 200, all from solidly Republican states. But there remain a number of so-called battleground states that Mr Trump could sweep for an unlikely victory on Nov 8.

Meanwhile, Ms Clinton remains vulnerable to the fabled October surprise, a late set of damaging revelations in a presidential campaign or a scandal that could vaporise the Democratic nominee’s lead in the polls. The announcement on Friday afternoon by FBI Director James Comey that more emails from Ms Clinton’s tenure as Secretary of State are to be examined by the FBI caused the Dow Jones Industrial Average to plummet in the minutes after the news.

Outside Trump Tower in Manhattan, the energy is palpable. Sixteen months ago Mr Trump famously descended an escalator in the glittering lobby to announce an unlikely presidential bid. He has ten days left to convince American voters that a historic, wild and unpredictable campaign should end in victory.