Both are Nobel Peace Prize winners. Obama accepted his party's nomination for president on the 45th anniversary of King's famous speech at the March on Washington for Jobs and Freedom in 1963.
Earlier this year, Obama added a new decoration to the Oval Office - a bronze bust of the slain civil rights leader. After his community organizing days in Chicago, Obama drew inspiration from reading "Parting the Waters," the first installment of Taylor Branch's multivolume biography of King.
So, what advice would King give Obama today had King not been killed by an assassin's bullet in 1968?
Would King, who lived by the code of nonviolent change, be alarmed by Obama's escalation of the war in Afghanistan?
Would King praise Obama for his efforts to provide health care for millions of Americans?
Would King join the critics who charge Obama hasn't done enough to fight racial and economic inequality in America?
We pose these questions to civil rights activists, scholars, clergy and politicos. To them, the issues that King worked tirelessly on four decades ago should be at the top of Obama's agenda today.
"I refuse to accept the view that mankind is so tragically bound to the starless midnight of racism and war that the bright daybreak of peace and brotherhood can never become a reality," King said in accepting his Nobel Peace Prize in 1964.
"I have the audacity to believe that peoples everywhere can have three meals a day for their bodies, education and culture for their minds, and dignity, equality and freedom for their spirits."
Elaine Gross, president of the Syosset-based regional advocacy group ERASE Racism:
"Help your congressional allies understand what is necessary for our economic system to work for all Americans, not just the wealthy. Communicate those needed changes for real economic health and family-supporting jobs to the nation.
"Go forward with thoughtful withdrawal in Iraq. Despite a carefully deliberated decision to increase troops in Afghanistan, ask yourself if all-out war there is the best way to curtail terrorists who can launch their violence from anywhere.
"Speak directly to the people to improve race relations. When action is required, intervene! Establish an agenda."
DuWayne Gregory, legislator for the 15th District in southwest Suffolk County:
"He would probably remind President Obama of his campaign comments on not having blue or red states but only purple states, united for a more prosperous future.
"He would recommend that we pull out of those two countries so they could settle their own problems and not see us as an occupying force.
"He would advise the president to convene forums on racism, even if some people misguidedly saw that as working only for black people. He would remind him that people should be judged 'on their character, rather than the color of their skin.' "
Calvin Butts, president of SUNY at Old Westbury and pastor of Harlem's Abyssinian Baptist Church:
"He would say take the money being spent on military aggression and invest it heavily in education and health care.
"Consistent with his stance on nonviolence, Martin Luther King Jr. would tell the president to pull us out of the wars.
"It's like a man strung out on drugs; he has to first acknowledge there's a problem. Obama would have to come to grips with America's racism and stop tiptoeing around it."
Delano Stewart of Wyandanch, a community advocate and publisher of a local biweekly newspaper, Point of View:
"As a man who lost his life during an effort to gain a living wage for garbagemen, he would counsel the president to make economic equity his priority, even though that could cost him a second term.
"He opposed the Vietnam War, but that did not threaten the homeland. So I believe he would press Obama to pursue dialogue, while strengthening defensive efforts.
"I believe King would counsel President Obama to promote dialogue on racism by refusing to give in to the uproar that drowns out voices like former President Jimmy Carter, who dared to warn of racism in the Birther and Tea Party movements."
Luis Valenzuela, executive director of Long Island Immigrant Alliance, said:
"I think he would tell him that responsible leadership uses a platform of universal human rights to make sure that every resident of the nation is included in the social benefits of what is produced.
"Clearly he would tell him to find the means necessary to put an end to these wars as quickly as possible. King said there's no way to wage war to make peace. You make peace to end wars.
"To engage in a frank and open national discussion about institutional racism, which is quite different from the racism of yesterday. Today's racists don't go riding around in sheets and hoods. Today's racism is part of the structure of our society. For example, on Long Island we have hyper-segregated living situations. The disparities in all social indicators are wide and continuing to widen. . . . Those types of disparities are facilitated by institutional racism."
Hazel N. Dukes, president of the NAACP's New York State Conference:
"He would continue with his legacy of saying that we are members of the human race and should continue that long struggle of trying to get all the races to respect each other. That's what America is made of - a melting pot.
"He would be absolutely saddened about . . . [the wars in Iraq and Afghanistan]. He was against the Vietnam War. But he did want to keep this nation and all nations safe. I'm sure he would say to him that 'Let's find other methods without taking lives or losing lives.'
"He would say continue to meet with and bring in religious, civic and human rights leaders of various backgrounds and diversity to see if we could continue to work toward a common goal of seeing all men and women created by God and being equal."
"He would say the problems you are confronting today are monumental and so I remind you to always find strength in your faith in God. And to also never forget that all human beings are God's children and need the help that you as president and all of those who advise you can give.
"The prophet Isaiah offers a vision of a time when guns and mortars will be turned into plowshares and instruments of peace, and so I ask you to do all you can to make that day a reality, but to do it in such a way that America and all that we stand for remains strong.
"Be sure to send out a very clear message that there is certain speech and actions on the part of any American, no matter who that person is, that are unacceptable, and you as an individual and as president will not accept that from anyone and will quickly and strongly point that out."
"I think he would tell him to focus more on the needs of the people, rather than the needs of corporate interests.
"There has to be other options other than war, and ultimately it's not about policy as much as it is about the people of America.
"Race relations is about community, and after 9/11 often during times of war American citizens huddle toward its leadership and I think he would advise the president that, despite all of these things . . . the focus has to be that of humanity and taking care of the immediate needs of its citizens."