NEW YORK: US society is uncomfortable with powerful women and that is why the United States has not yet elected a woman president, US President Barack Obama said on Sunday. Obama, who is eager to see fellow Democrat Hillary Clinton succeed him in office, told a fundraiser for her in New York that the election between his former secretary of state and Republican businessman Donald Trump should not be close. However, political polarisation in the country would make it tight, he said. The first African-American US president then told the group of donors why he thought a woman had never held the office. 'There's a reason why we haven't had a woman president,' he said. 'We as a society still grapple with what it means to see powerful women. And it still troubles us in a lot of ways, unfairly. And that expresses itself in all sorts of ways.' Obama has often spoken about the role of strong women in his life, including his mother, grandmother, wife and daughters. Polls have tightened between Clinton, a former US senator and first lady, and Trump, a real-estate tycoon. 'This should not be a close election, but it will be,' Obama said. 'And the reason it will be is not because of Hillary's flaws, but rather because, structurally, we've become a very polarised society,' he said. The president has not hidden his disdain for Trump, who was one of the leaders of the movement that questioned whether Obama was born in the United States. Trump conceded on Friday that Obama was US born. Obama told the donors that Trump was unlike the two candidates he faced in the 2008 and 2012 general elections. 'When I ran against John McCain, we had deep differences, but I couldn't say that he was not qualified to be president of the United States,' Obama said of his 2008 opponent. 'I couldn't say that electing Mitt Romney would be an unmitigated disaster. This guy (Trump) is not qualified to be president.'