She said she spoke from personal experience. Her mother, who fled to India from Pakistan as a refugee during the riots following India's independence and is now an American citizen, is disabled with severe osteoporosis.

According to a recent article in the New York Times, the president receives over 10,000 letters, e-mails and faxes every day. The task of sifting these letters goes to Mike Kelleher, director of the White House Office of Correspondence.

Kelleher chooses 10 letters which are slipped into a purple folder and put in the daily briefing book that is delivered to President Obama at his White House residence.

'We pick messages that are compelling, things people say that, when you read it, you get a chill,' Kelleher told the Times. 'I send him letters that are uncomfortable messages.'

The ritual offers President Obama a way to move beyond the 'White House bubble', and occasionally leads to moments when his composure cracks, his advisers told the paper.

The White House chief of staff, Rahm Emanuel, said President Obama 'believes it's easy in Washington to forget there are real people with real challenges being affected by the debate'.

Emanuel added that he had seen the president turn to policy advisers in meetings and say 'no, no, no. I want to read you a letter that I got. I want you to understand.'