President Barack Obama has marked a frenetic first 50 days in office, making education his latest testbed for reform, as a torrent of economic crises crests around him.

Half-way through his symbolic first 100 days, Obama has unleashed a quest to reframe US foreign, social, economic, military and energy policy, even as America's trademark optimism reels from stunning job losses and stockmarket slumps.

"Every so often, throughout our history, a generation of Americans bears the responsibility of seeing this country through difficult times and protecting the dream of its founding for posterity," Obama said Tuesday.

"This is a responsibility that's fallen to our generation. Meeting it will require steering our nation's economy through a crisis unlike anything that we have seen in our time."

The president insists that testing times require a daring response, promising to spend more than a trillion dollars to revive the comatosed economy, save the finance industry and keep threatened mortgage holders in their homes.

Obama drove his 787-billion-dollar stimulus plan through Congress at an impressive clip, though Republican defections soured his hopes of leading a new post-partisan political era.

He ordered the closure of the Guantanamo Bay prison camp, brought the United States full bore into the battle against global warming and unleashed a wave of reform aimed at issues like healthcare and the gaping budget deficit.

On Monday, he overturned Bush adminsitration curbs on federal funding for stem-cell research.

Internationally, Obama stamped an end date on the Iraq war -- August 31, 2010, and ordered 17,000 more US troops into Afghanistan, with the possibility of more to come as a Pakistan-Afghan policy review winds up.

The president also signed off on exploratory contacts with US foes -- inviting Iran to a conference on Afghanistan and sending envoys to Syria.

He also renewed a US push for Israeli-Palestinian peace.

So far, voters seem to be giving their new president the benefit of the doubt, with approval ratings of around 60 percent in most polls, about average for a new president.

Despite touting progress, even Obama's top aides admit 50 days is a mere snapshot.

Obama "understood that not all our challenges would be met in 50 days, that there would be much work to do," his spokesman Robert Gibbs said.

That caution may be well placed, as warning signs spell danger for the new administration.

Debt-laden US banks remain the epicenter of the eocnomic crisis and it is still not clear the administration knows how to fix them.

Treasury Secretary Timothy Geithner has endured a pounding, after his initial attempt to explain the Obama banking plan foundered, and underwhelmed the markets.

It is still not clear whether the administration will eventually be forced into nationalizing parts of the industry, will throw billions more dollars at the banks, or will work out how to deal with toxic assets.

An unappealing choice appears to be looming on whether to shell out more government cash to the iconic "Big Three" auto firms or let them die.

Though administration officials deny fluctating stocks are a measure of Obama's progress, the markets have tumbled during his presidency.

On January 16, the last day of trading during the Bush administration, the Dow Jones Industrial Average closed at 8,281.22.

After 50 days under Obama -- and dragged down partly by economic turmoil not of his making -- the Dow closed at 6,926.49, despite a 5.8 percent rally Tuesday.

The scale of Obama's 3.55 trillion dollar budget revealed his sizable plans, but horrified critics.

"The budget he's proposed for this nation, I think is a radical, reckless exercise in fiscal discipline," Republican Senator Lindsey Graham said summing up Obama's first 50 days on CNN Tuesday.

"Overall, I would give him poor marks in terms of financial management. But there are some ideas, like health care reform as being a priority, and Social Security solvency, I do agree with him, and want to help him where I can."

Obama has also run into claims he should be doing nothing but trying to save the economy.

But the president, arguing that sustainable economic recovery needs bold political reformn, hit back at his critics, as he unveiled his education plans.

"I know there are some who believe we can only handle one challenge at a time," Obama said, before arguing that great US presidents Abraham Lincoln, Franklin Roosevelt and John Kennedy did great things, despite crises.