(CNN) -- Sen. Barack Obama and Sen. Hillary Clinton, rivals for the Democratic presidential nomination, focused on economic justice in speeches Friday marking the anniversary of the Rev. Martin Luther King Jr.'s assassination.
Clinton and the presumptive Republican nominee, Sen. John McCain, spoke to audiences in Memphis, Tennessee, where King was killed 40 years ago.
Obama, the Illinois senator who hopes to become the first black president, downplayed race in his speech in Fort Wayne, Indiana.
"Dr. King understood that the struggle for economic justice and the struggle for racial justice were really one -- that each was part of a larger struggle 'for freedom, for dignity and for humanity,' " Obama said, pointing out that King had been in Memphis, Tennessee, to support striking sanitation workers when he was killed.
Obama noted an economic report released Friday said the American economy lost 80,000 jobs last month. Watch Obama remember King »
"Just this morning, it was announced that more Americans are unemployed now than at any time in years," he said.
Obama was speaking to a racially mixed crowd of a few thousand at a campaign town hall meeting.
Before the speech, he said he was not concerned about how his absence from Memphis would be interpreted.
"I spoke at Dr. King's church on his birthday. I was with the King family then. I obviously gave a fairly fulsome speech on the state of race relations just two weeks ago. And I think it's important to spread the message that Dr. King's work is unfinished in places like Indiana and North Dakota," he said.
She became visibly emotional as she remembered hearing King had been shot. Watch Al Sharpton and Jesse Jackson on Obama honoring King
Like Obama, she emphasized economic justice in her remarks.
"I believe we should appoint a Cabinet-level position that will be solely and fully devoted to ending poverty as we know it in America," she said, "a position that will focus our attention on the issue in this nation and never let it go." She said King's message was universal.
"When he stood against discrimination, he was not just speaking for African-Americans he was seeking to break the shackles of hatred on the hearts of us all."
McCain spoke in Memphis at a meeting of the Southern Christian Leadership Conference, a civil rights organization closely associated with King, and said he was wrong to have opposed a national holiday honoring the civil rights leader. Watch McCain speak about King
"We can be slow as well to give greatness its due, a mistake I made myself long ago when I voted against a federal holiday in memory of Dr. King. I was wrong and eventually realized that," McCain said. He has expressed regret for his stance previously. McCain says he was mistaken to oppose King holiday
President Bush issued a statement marking the anniversary.
"Forty years ago today, America was robbed of one of history's most consequential advocates for equality and civil rights," he said. "We have made progress on Dr. King's dream, yet the struggle is not over. Ensuring freedom and equality for all Americans remains one of our most important responsibilities." E-mail to a friend