WASHINGTON — President Barack Obama prodded Congress to raise wages and secure the social safety net as he issued an overarching appeal Wednesday to correct economic inequalities that he said make it harder for a child to escape poverty. “That should offend all of us,” he declared. “We are a better country than this.”

Focusing on the pocketbook issues that Americans consistently rank as a top concern, Obama argued that the dream of upward economic mobility is breaking down and that the growing income gap is a “defining challenge of our time.”

“The basic bargain at the heart of our economy has frayed,” the president said in remarks at a nonprofit community center a short drive from the White House in one of Washington’s most impoverished neighborhoods.

Though he offered no new initiatives, Obama blended a call for Congress to act on pending short-term economic measures with an ambitious vision aimed at rectifying a growing level of income inequality in the United States. Amid public doubts over Obama’s stewardship of the economy, the speech served as a guide for the remaining three years of his term.

Still, by drawing attention to past policy proposals that have dead-ended in a divided government, Obama also laid bare the political failures and economic difficulties he has faced trying to halt widening inequality trend