President Obama sought to rally support for his domestic initiatives, while Sen. John McCain called for Americans to support millions of Iranian election protesters.

The onetime presidential rivals both cited the spirit of the nation's founders in their U.S. Independence Day radio and Internet addresses Saturday.

Obama said an "unyielding spirit is what defines us as Americans" and led people during the nation's history to explore the West, persevere during the Depression and build a robust industrial economy.

"That is the spirit we are called to show once more," Obama said. "We are facing an array of challenges on a scale unseen in our time. We are waging two wars. We are battling a deep recession. And our economy -- and our nation itself -- are endangered by festering problems we have kicked down the road for far too long: spiraling health care costs; inadequate schools; and a dependence on foreign oil."

He said the same spirit will be needed to deal with problems "we cannot defer any longer," citing several areas:

--Revamping the education system, demand more from teachers, parents and students and "build schools that prepare every child in America to outcompete any worker in the world."

--Overhauling the health care system "that is imposing crushing costs on families, businesses, large and small, and state and federal budgets."

--Making clean energy "the profitable kind of energy so that we can end our dependence on foreign oil and reclaim America's future."

The House narrowly passed Obama's energy bill, and Congress is developing legislation to overhaul the health care system, making care more affordable and providing coverage for millions of the uninsured.

McCain, an Arizona Republican, says the United States has a moral obligation to publicly denounce the Iranian government and support Iranians who feel cheated by the election.

"Today, we stand with the millions of Iranians who brave batons, imprisonment and gunfire to have their voices heard and their votes counted," McCain said. "They do not ask us to arm them or come to their assistance with anything other than public declarations of solidarity, and public denunciations of the tyrants who oppress them. We have a moral obligation to do so."

After quashing huge street demonstrations, Iran's leadership has been trying to erase any lingering doubts about the legitimacy of President Mahmoud Ahmadinejad by portraying the unrest as sparked by foreign meddling, not by public anger over the June 12 election, which the protesters said was fraudulent.

Obama has tried to balance being supportive of the protesters without giving the Iranian government more cause to crack down.

Republican lawmakers have pushed Obama to more forcefully denounce Iran's leadership. More than two weeks ago, the president issued his strongest statement against the actions of the Iranian regime. "No iron fist is strong enough to shut off the world from bearing witness to the peaceful pursuit of justice," Obama said at a news conference. He expressed doubt about the legitimacy of the national election.

While McCain on Saturday pushed for a more forceful international voice, Obama rallied support for his domestic programs.

Obama said some critics of his programs "would have us try what has already failed; who would defend the status quo."

But he said those critics need to remember history.

"They forget that we, as a people, did not get here by standing pat in a time of change," he said. "We did not get here by doing what was easy. That is not how a cluster of 13 colonies became the United States of America."

"We are not a people who fear the future. We are a people who make it," Obama said. "And on this July Fourth, we need to summon that spirit once more."