Donald Trump’s chances of winning presidential election narrowing as polls continue to swing Hillary Clinton’s way

An increasingly confident Hillary Clinton has given full marks to running mate Tim Kaine for his sustained battering of Mike Pence, the Republican running mate, in their debate, even as he was scored the loser by most pundits and instant polls.

Both camps declared victory after the often testy encounter between the two vice presidential hopefuls in Virginia on Tuesday, though the relief was more audible among Republicans who needed respite after Donald Trump stumbled in his first debate with Ms Clinton last month.

Ms Clinton’s post-debate bounce continues to gather strength. On Wednesday a new Ispos-Reuters poll showed her with a six per cent lead nationally, one point higher than a CNN-ORC survey released on Tuesday. In several swing states she may be also vaulting ahead.

That the momentum remains clearly with the Democrat will only serve to pile pressure on Mr Trump who will face her in a second debate in St Louis, Missouri, on Sunday. That debate will be in a town hall-type format, with candidates fielding questions from audience members.

The recent downward slide of the Republican can be traced to that first debate with Ms Clinton at Hofstra University in New York on 26 September but also to the serial wounds, some self-inflicted, that he suffered in the days that followed.

First Mr Trump chose to persist in attacking a former Miss Universe contestant who Ms Clinton had identified as a victim of his disdain during the debate, including with a barrage of pre-dawn tweets, a continuing drama that was eclipsed only by reports last weekend that he may have avoided paying income taxes for almost two decades after losing more than $900m in 1995.

The window for Mr Trump to reverse the dynamics of the race is now perilously narrow. There is barely one month left of campaigning until election day. However, as many as 40 per cent of voters are expected to hand in their ballots well before then. Early voting is already under way in battleground states such as Iowa and Wisconsin and is about to start in Florida and North Carolina.

The vice-presidential debate was a boisterous one, marked by Mr Kaine repeatedly demanding that Mr Pence, who is the Governor of Indiana, offer a defence for assorted controversies created by Mr Trump on the campaign trail, whether demeaning women, smearing Mexicans, saying that his success in avoiding taxes made him “smart” and questioning President Barack Obama’s citizenship. It all added up, he said, to Mr Trump running an “insult-driven” campaign.

He also pressed Mr Pence on Mr Trump publicly suggesting Japan and Saudi Arabia should consider acquiring nuclear weapons and his stated admiration for Vladimir Putin.

“As a candidate, [Trump] started his campaign with a speech where he called Mexicans rapists and criminals and he has pursued the discredited and really outrageous lie that President Obama wasn’t born in the United States,” Mr Kaine said. “I can’t imagine how Governor Pence can defend the insult-driven, selfish, me-first style of Donald Trump.”

Mr Pence, once a radio broadcaster, remained unruffled, serially accusing his opponent of misstating the facts. But he also separated himself from the man at the top of his ticket, notably playing up the danger that a newly aggressive Russia represented for the word, though blaming it on what he called the “weak and feckless” foreign policy of Mr Obama and Ms Clinton.

Mr Trump's campaign manager Kellyanne Conway said on Wednesday that Mr Kaine acted “like he had a tic” by mentioning the Republican nominee so frequently in the debate. But boarding a plane near her New York home as she prepared to fly to Washington, Ms Clinton flashed a two-thumbs-up sign when asked how her running mate had performed.

His most effective moment may have been pressing Mr Pence on the issue of Mr Trump’s tax affairs and his refusal to release his returns. The Republican responded, as other Republicans have, by suggesting the evasion of federal taxes was proof of Mr Trump’s business acumen.

“His tax returns – his tax returns showed he went through a very difficult time, but he used the tax code just the way it’s supposed to be used,” Mr Pence attempted, before adding the slightly rash assertion: “And he did it brilliantly.”

Suggestions on Wednesday that Mr Trump may actually have felt peeved that Mr Pence had shown him up as the worse debater were furiously rejected by his campaign.

“That’s just not true,” Ms Conway told MSNBC. “His last tweet last night was how excited he was, how proud of him he was. They talked last night. I talked to Mr Trump during the debate several times.”

The Democrat team was moving on, however, with Ms Clinton excusing herself from the trail so she can concentrate on debate preparation before Sunday, while her main surrogates, including Chelsea and Bill Clinton, were fanning out to swing states to try to ensure that the momentum towards victory that has now come into view can be sustained.

Most hopeful for her team were signs that she is pulling ahead in the key states of Florida, North Carolina and Pennsylvania. Mr Trump appeared to be maintaining a small lead in Ohio, but without the Sunshine State in particular, final victory on 8 November is likely to remain elusive.

“What gives me confidence right now is we have a number of different paths to the White House,” Clinton campaign manager Robby Mook told Politico. “I feel good about our prospects in all these battleground states right now, in part because of the ground game we have put in place, but the bar is really high for Donald Trump. I would argue he has to win Florida, he has to win North Carolina, he probably has to win Pennsylvania. And that’s a very narrow path.”