Obama also said the widening income inequality and the lingering effects of the financial crisis have frayed America's social fabric and undermined Americans' belief in opportunity.
"I will seize any opportunity I can find to work with Congress to strengthen the middle class, improve their prospects, improve their security," he said.
Obama, 51, now in the seventh month of his second innings at the White House, he vowed not to be cowed by his Republican adversaries in Congress and said he was willing to stretch the limits of his powers to change the direction of the debate in
"I'm not just going to sit back if the only message from some of these folks is no on everything, and sit around and twiddle my thumbs for the next 1,200 days," Obama told The New York Times.
Speaking a few days after the acquittal in the Trayvon Martin case prompted him to speak about being a black man in America, Obama said the country's struggle over race would not be eased until the political process in Washington began addressing the fear of many people that financial stability is unattainable.
"Racial tensions won't get better; they may get worse, because people will feel as if they've got to compete with some other group to get scraps from a shrinking pot," he said.
"If the economy is growing, everybody feels invested. Everybody feels as if we're rolling in the same direction."
Upward mobility, "was part and parcel of who we were as Americans. And that's what's been eroding over the last 20, 30 years, well before the financial crisis," Obama said.
"If we don't do anything, then growth will be slower than it should be. Unemployment will not go down as fast as it should. Income inequality will continue to rise," he said, underlining that "that's not a future that we should accept."
The US economy is "far stronger" than four years ago, he said, yet many people who write to him still do not feel secure about their future, even as their current situation recovers.
"That's what people sense," he said. "That's why people are anxious. That's why people are frustrated."
Without a shift in Washington to encourage growth over "damaging" austerity, Obama added, not only would the middle class shrink, but in turn, contentious issues like trade, climate change and immigration could become harder to address.
Obama also called for an end to the emphasis on budget austerity that Republicans ushered in when they captured control of the House of Representatives in November 2010.
The priority, he said, should be spending for infrastructure, education, clean energy, science, research and other domestic initiatives of the sort he twice campaigned on.
He called for a shift "away from what I think has been a damaging framework in Washington."
Even as he spoke, House Republicans were pushing measures in the opposite direction: to continue into the fiscal year that starts October 1 the indiscriminate across-the-board spending reductions ' known as sequestration ' that Obama opposes, and to cut his priorities deeper still.
Republicans are also threatening to block an increase in the government's borrowing limit - an action that must be taken by perhaps November to avoid financial crisis - unless Congress withholds money for his health care law.
Obama all but dared Republicans to challenge his executive actions, including his decision three weeks ago to delay until 2015 the health care law's mandate that large employers provide insurance or pay fines.
"If Congress thinks that what I've done is inappropriate or wrong in some fashion, they're free to make that case," he said. "But there's not an action that I take that you don't have some folks in Congress who say that I'm usurping my authority. Some of those folks think I usurp my authority by having the gall to win the presidency."