It was a photograph that for many summed up that there is nothing more natural than a woman breastfeeding her baby.

Indeed, after Margaret Bradford was photographed feeding her daughter during the middle of a Bernie Sanders rally, the Vermont senator’s campaign tweeted the image, saying nobody should be stigmatised for feeding their child in public.

The photo inspired the hashtag #BoobsForBernie and new mothers across the US have shared images of themselves and their children.

Hi Ellen DeGeneres!This past week my daughter and I got to attend a U.S. Senator Bernie Sanders' rally. While there,... Posted by Margaret Ellen Bradford on Wednesday, 2 March 2016

But not everyone felt that way. In message posted on Facebook, Ms Bradford said that while she had received lots of supportive messages since the picture was taken at Barberton, Ohio, there had been hate mail as well.

“While there, she got hungry like babies do,” she wrote, adding that she was not aware she was being photographed at the rally.

“Honestly I’ve cried three times already from some of the hateful messages I’ve received, telling me my daughter should be taken or that I’m just an uneducated lowlife hick.”

Public breastfeeding has been a divisive issue in recent years. In 2014, a mother in Beverly Hills claimed that she was escorted to a bathroom while shopping at a department store while breastfeeding. And in Beaverton, Oregon, a group of mothers staged a “nurse-in” at a restaurant to protest a breastfeeding mom who was asked to cover up.

CNN said that breastfeeding rates in the U.S. are rising, according to the 2014 Breastfeeding Report Card from the Centres for Disease Control and Prevention.