WASHINGTON (AP) -- The tasks stacking up before President Barack Obama over the coming weeks will test his persuasion powers and his mobilizing skills more than any other time in his presidency.
How well Obama handles the challenges in the concentrated amount of time before him could determine whether he leads the nation from a position of strength or whether he becomes a lame duck one year into his second term.
Between now and the end of October, Obama must convince wary lawmakers that they should grant him authority to take military action against Syria; take on Congress in an economy-rattling debate over spending and the nation's borrowing limit; and oversee a crucial step in the putting in place his prized health care law.
The Syria vote looms as his first, biggest and perhaps most defining challenge. His mission is persuading Congress -- and bringing the public along -- to approve armed action against the Syrian government in response to a chemical attack that Obama blames on President Bashar Assad's government.
"It's conceivable that, at the end of the day, I don't persuade a majority of the American people that it's the right thing to do," Obama acknowledged in a news conference Friday.
His chief of staff, Denis McDonough, was asked on "Fox News Sunday" whether a congressional rejection might endanger Obama's presidency, and he responded: "Politics is somebody else's concern. The president is not interested in the politics of this."
Presidents tend to have an advantage on issues of national security, a tradition demonstrated by the support Obama has won for action in Syria from the bipartisan leadership of the House. But that has not translated so far into firm support among the rank and file.
"Congress can look presidents in the eye on a level gaze regarding the budget," the presidential historian H.W. Brands said. "But on war and peace they have to look up to the president, he's the commander in chief.
"If he does lose, even if the loss comes about partly as a result from negative Democratic votes, the Republicans are going to get the bit in their teeth and say 'We're not going to give this guy anything,'" said Brands, a professor at the University of Texas at Austin, said.
By that reasoning, success on Syria could give Obama some momentum.
"If he gets the authority it shows that he's not a lame duck, that he still has some power," said John Feehery, a Republican strategist and former House GOP leadership aide. "If he doesn't get the authority, it's devastating. People see him as the lamest of lame ducks."
The Syria vote, however, is unusual and probably will not break along traditional partisan or ideological lines. Democrats and Republicans have voiced support and opposition to a military intervention. As a result, some White House officials believe their ability to influence issues that split along party lines is limited.
"It becomes more of a stand-alone," said Republican pollster David Winston, who advises House Republican leaders. "This is a decision distinct from internal domestic politics."
At the White House, Syria for now has eclipsed all other matters.
Obama spent the last two days in St. Petersburg, Russia, trying to build a coalition of support from among the members of the Group of 20 largest economies. Back home, Defense Secretary Chuck Hagel and Secretary of State John Kerry made their case to lawmakers in public and in private while Obama lobbied individual members by telephone.
On Tuesday, Obama will speak to the nation during an evening address from the White House, a rare forum reserved for the weightiest of issues. The speech will come a day before the Senate holds its first showdown vote over a resolution authorizing the "limited and specified use" of U.S. armed forces against Syria. The resolution bars the use of U.S. combat troops. A final Senate vote could come at the end of the week. The House would likely take the measure up the following week.
Win or lose, Obama and lawmakers then would run headlong into a debate over the budget.
Congress will have a limited window to continue government operations before the new budget year begins Oct. 1.
Congressional leaders probably will agree to hold spending at current budget levels for about two months or three months. That would delay a confrontation with the White House and pair a debate over 2014 spending levels with the government's need to raise its current $16.7 trillion borrowing limit. The Treasury says the government will hit that ceiling in mid-October.