Trump camp hits Clinton for Bill's past

Democratic presidential nominee Hillary Clinton and Republican presidential nominee Donald Trump shake hands during the presidential debate at Hofstra University. Photo / AP

Donald Trump announced at the first presidential debate that he would not be "extremely rough" to Hillary Clinton and her family. He explained later that he meant he wouldn't bring up examples of former President Bill Clinton's infidelity.

Trump's surrogates have no problem doing it for him.

Former New York Mayor Rudolph Giuliani, one of Trump's closest advisers, said Hillary Clinton is "too stupid" to be president because she appeared to not know her husband was unfaithful to her. David Bossie, Trump's deputy campaign manager, accused Clinton of being an "enabler". And Arkansas Attorney-General Leslie Rutledge questioned Hillary Clinton's "treatment of women" involved with her husband.

In better news for Clinton, the first poll survey after the debate - by NBC and SurveyMonkey - found that the Democratic nominee was considered by voters to have won it, 52 per cent to Trump's 21 per cent. Another 26 per cent said neither. At least five snap polls had earlier said Clinton won the debate.

There were also early indications that Clinton had received a poll bounce. Political forecaster Nate Silver of FiveThirtyEight tweeted: "First three fully post-debate national polls have Clinton +5, +4, +3. So I'll daringly assert she might settle into a 3-5 point nat'l lead."

In Durham, New Hampshire, Clinton promised young voters that she will champion issues they care about, especially the crushing cost of college, as she and former rival Senator Bernie Sanders appealed to an age group that has never fully warmed to her. "Today I am asking all of you to think big, not small," Sanders said.

Michelle Obama stumped for Clinton in Philadelphia, tearing into Trump for "erratic and threatening" behaviour that would put the country at risk. Never mentioning Trump by name, she said the Republican presidential nominee "traffics in prejudice, fears and lies" and insults women.

She said Clinton is "clearly the only person in this race who has any idea what this job takes". What the country needs is "an adult in the White House".