Mahatma Gandhi is among the most quoted historical figures of all time. But few outside India bring him up as often as U.S. President Barack Obama.

The President quoted him most recently in his address at the United Nations General Assembly in New York.

“It’s time to heed the words of Gandhi: ‘Intolerance is itself a form of violence and an obstacle to the growth of a true democratic spirit.’ Together, we must work towards a world where we are strengthened by our differences, and not defined by them,” said Mr. Obama last week as he called for greater tolerance in the wake of an anti-Islam video that sparked violence across the Muslim world.

Predictably, Gandhi was also a recurring theme during Mr. Obama’s visit to India two years ago. In a trip that didn’t have a particularly Gandhian flavor otherwise –  it centered largely on defense and business deals – the President paid his respects at Gandhi’s Mumbai home and his grave in Delhi. And, in his address to the Indian Parliament, Mr. Obama mentioned him six times, describing him as an early, defining influence: “Throughout my life, including my work as a young man on behalf of the urban poor, I’ve always found inspiration in the life of Gandhiji and his simple and profound lesson to be the change we seek in the world.”

There’s more to Mr. Obama’s fascination with Gandhi than a general interest in him as an icon of peace and freedom. It also has to do with Gandhi’s influence on Rev. Martin Luther King Jr.

In 2009, when a student asked Mr. Obama who he would most like to have dinner with, dead or alive, the President picked the Indian freedom fighter: “He’s somebody who I find a lot of inspiration in. He inspired Dr. King, so if it hadn’t been for the non-violent movement in India, you might not have seen the same non-violent movement for civil rights here in the United States.”

Dr. King had listed a biography of Gandhi among a handful of books that most influenced his thinking, and, in a 1957 letter, described “the Gandhian philosophy of nonviolent resistance” as “the only logical and moral approach to the solution of the race problem in the United States.”

Two years later, Dr. King spent a month in India – a trip Mr. Obama described as a “pilgrimage” – where he met then-Prime Minister Jawaharlal Nehru, learned about policies to address caste-based discrimination and even visited ashrams. 

Dr. King’s time in India strengthened his commitment to the principle of nonviolence as a way of fighting racial discrimination in the U.S. “Since being in India, I am more convinced than ever before that the method of nonviolent resistance is the most potent weapon available to oppressed people in their struggle for justice and human dignity,” he said in a farewell address broadcast on Indian radio in March 1959.

Dr. King never met Gandhi, who died over a decade before his trip to India.

As the first African-American President of the United States, Mr. Obama sees himself as a direct product of the struggles of both men. “As someone who stands here as a direct consequence of Dr. King’s life work, I am living testimony to the moral force of non-violence.  I know there’s nothing weak — nothing passive — nothing naïve — in the creed and lives of Gandhi and King,” he said in his Nobel Peace Prize acceptance speech in 2009.

Of course, Gandhi is mentioned countless times in speeches by Indian politicians. Most recently, Indian Prime Minister Manmohan Singh brought up Gandhi in a speech focused on economic growth and corporate governance. His message? To remind business folks that morality is an important part of enterprise.