President Obama, speaking at an event Sunday in New York City, said that a bias against powerful women could hurt Democratic presidential nominee Hillary Clinton with voters in November.

“There’s a reason why we haven’t had a woman president,” Obama said at the fundraiser for Clinton. “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.”

In his brief remarks, Obama touted his administration’s achievements over the past eight years, praised Clinton and blasted Republican nominee Donald Trump as unfit to be president as he has repeatedly in recent weeks. His remarks about Americans' reluctance to support a powerful woman were among his strongest on the subject and come amid polls showing that the race is tightening.

“This should not be a close election but it will be, and the reason it will be is not because of Hillary’s flaws,” he said.

In addition to sexism, Obama singled out the deep partisan divide as another reason for what he said is likely to be a close election. “Structurally we already have these divisions,” Obama said. “It is going to be hard to overcome those.”

Obama contrasted Trump with the two previous Republican nominees – both of whom he described as qualified to serve as president. “I couldn’t say that electing Mitt Romney would be an unmitigated disaster,” he said.

Obama described Trump as someone who “shows no interest in even gaining the rudimentary knowledge required to make really hard decisions” and whose campaign has sought to exploit the country’s worst and most divisive impulses.

“It is an infomercial. It’s a reality show,” Obama said of the Trump campaign.

The president on Sunday also pointed to recent statistics from the U.S. Census Bureau that showed that middle-class and poor Americans had their best year of income gains in decades as proof that his economic polices are working.

“We now have one candidate in this race who is prepared to carry on that kind of governance,” Obama said, referring to Clinton.

Sunday's fundraiser was held at the home of Audrey and Danny Meyer, who is the chief executive of the Union Square Hospitality Group, which includes the restaurants Shake Shack and Gramercy Tavern, among others. The event drew about 65 attendees who contributed $25,000 each. The co-chairs contributed $100,000 and the chairs raised or contributed $250,000.