OSAWATOMIE, Kan. - With a nod to Theodore Roosevelt, President Obama positioned himself as the champion of the middle class while blasting the "you're-on-your-own economics" of the modern Republican Party, a message likely to form the basis of his reelection effort.

The White House chose what seemed like an unlikely site for Obama's speech, a small town in deeply Republican Kansas.

To Obama's advisers, it was the ideal place to deliver an argument they had spent weeks crafting, one that they hope will help him appeal to a key bloc. It was here, 101 years ago, that Roosevelt outlined his agenda of "new nationalism" - a call for progressive reforms and an active federal government committed to reining in the power of concentrated wealth.

In his remarks, Obama acknowledged the hardship many Americans face and called this a "make-or-break moment for the middle class."

"This is the defining issue of our time," he said. "At stake is whether this will be a country where working people can earn enough to raise a family, build a modest savings, own a home, and secure their retirement."

Obama's theme, which White House advisers hope will draw centrist voters, is that today's GOP leadership has abandoned the party's legacy in favor of defending the interests of the powerful.

The president said some "seem to be suffering from a kind of collective amnesia."

"In fact, they want to go back to the same policies that have stacked the deck against middle-class Americans for too many years," he said. "I believe that this country succeeds when everyone gets a fair shot, when everyone does their fair share, and when everyone plays by the same rules. Those aren't Democratic or Republican values, 1 percent values or 99 percent values. They're American values, and we have to reclaim them."

Republicans scoff at Obama's efforts to align himself with Roosevelt, whose calls for corporate reform came at a time when there was little business regulation.

Obama's team argues he is embracing the spirit of Roosevelt's beliefs in a modern context. The president pointed to actions in a Republican administration last decade to pass "tax cuts for the wealthy" and slash oversight.

"And what did they get us? The slowest job growth in half a century. Massive deficits that have made it much harder to pay for the investments that built this country," he said, and "a financial sector where irresponsibility and lack of basic oversight nearly destroyed our entire economy."

"We simply cannot return to this brand of you're-on-your-own economics if we're serious about rebuilding the middle class in this country," he said.