President Obama won't formally lay out his second-term agenda until his inaugural address later today, but the president has already made clear some of the major issues he intends to take on over the next four years. He has signaled that his focus in the short-term is on passage of corporate tax reform and new gun control laws as well as comprehensive immigration reform legislation. Over the long term, Mr. Obama plans to continue focusing on the nation's fiscal issues - including potentially achieving the elusive "grand bargain" to address the debt and deficit - continue the transition out of Afghanistan, and help shepherd the implementation of the health care law, which has a number of major provisions that kick in next year.

As he works toward these goals, Mr. Obama will also have to fend off the sort of major second-term setbacks that have hampered his predecessors as they tried to push their post-reelection agenda. That could be harder than you might think: Such setbacks have occurred so often that they've given rise to a nickname - the "second-term curse" - that has been applied to every reelected president dating back to Franklin Roosevelt.

Sometimes, the "second-term curse" is invoked in reference to a scandal: Richard Nixon and Watergate, Bill Clinton and Monica Lewinsky, Ronald Reagan and Iran-Contra. Sometimes it comes in the form of failure: Roosevelt and his plan to pack the Supreme Court, George W. Bush's effort to privatize Social Security. And sometimes it's a string of events: In addition to the Social Security debacle, Mr. Bush saw his legacy tarnished by fallout from the Iraq war and the government's response to Hurricane Katrina.

"Second-term presidencies, at least since World War II, have always been plagued by some kind of mistakes or scandal," said Ken Duberstein, who served as Reagan's White House chief of staff. Duberstein attributed that fact in part to "a tendency for hubris that if not checked goes toward overreach."

"Most second-term presidents seem to believe that they have perhaps a stronger mandate from the American people than they actually do," he said.

After he won reelection by 2.4 percentage points in 2004, Mr. Bush declared that "the people made it clear what they wanted," adding that he "earned capital in the campaign, political capital, and now I intend to spend it." He outlined his Social Security plan in February 2005 and campaigned for the proposal during a 60-day national tour - only to see support decline and congressional Republicans back away from the issue.

Stephen Hess, who served in the Eisenhower, Nixon, Ford and Carter administrations, said that a president needs to act "fairly quickly" in his second term, since Congress will soon be looking to the next election and treating the current president as a lame duck.

"It's like an hourglass with the sand running out," said Hess. The "lame duck" perception explains in part why presidents have historically focused more in international relations in their second term, an area where they have less dependence on winning over Congress.