barack_obama_107.jpgWASHINGTON (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 first 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.

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,'' agreed 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.

Obama has been adamant that he will not negotiate over the debt limit. He says a similar faceoff in 2011 hurt the economy and caused Standard & Poors to lower its rating of the nation's debt, which made it more expensive to borrow.

White House officials say they ultimately have leverage because they believe Republicans would be punished politically for playing brinkmanship and threatening the nation with a default.

The White House is counting on pressure from traditional Republican allies, particularly in the business sector. "It is insane not to raise the debt ceiling,'' U.S. Chamber of Commerce President Thomas Donohue said last week on C-SPAN. Donohue pledged to find primary challengers against lawmakers who threaten a default.

Conservative Republicans, particularly those aligned with the tea party, see the debt ceiling as an opportunity to defund or force a delay in the implementation of the Affordable Care Act, Obama's health insurance overhaul.

House Speaker John Boehner, R-Ohio, says any increase in the debt ceiling should be accompanied by reductions in spending, preferably in government benefit programs such as Medicare and Social Security. He has predicted "a whale of a fight.''

That dispute will play out against tepid economic growth, highlighted Friday by unemployment data that while lowering the jobless rate to 7.3 percent also showed that the proportion of Americans working or looking for work reached its lowest point in 35 years.

Obama, who once searched for a grand budget bargain with Boehner, has all but abandoned the effort for a big deal. An attempt to find common ground with a handful of Senate Republicans collapsed last week after Obama stuck with his insistence that any cuts in Medicare or Social Security had to be accompanied by higher taxes on the rich.

As a result, neither side is yet certain how they resolve their budget and debt-ceiling quandary.

As conservative Republicans keep up their effort to kill the health care law through the budget, the Obama administration will be in the middle of an aggressive recruitment effort to get primarily young and healthy people to enroll in health insurance exchanges, or marketplaces.

Starting Oct. 1, people who don't have health care coverage on their job can go to new online insurance markets in their states to shop for a private plan and find out if they qualify for a tax credit.

For the law to work millions will have to sign up by Jan. 1 and the exchanges will have to open without serious hitches that could undermine enrollment.

The administration has conducted an enlistment drive and is getting help from Obama's former re-election campaign to spur young people to sign up. Former President Bill Clinton has joined the effort to draw attention to the coming enrollment period and to address any confusion about the how the law works.

But in the end, it's Obama's law and the White House intends to capitalize on the president's appeal among young people to help drive sign ups in the market places.

The White House believes that as the law takes hold, its current unpopularity will fade and so will the drive to repeal it.

"A lot of the big defining successes are already in place,'' said Matt Bennett, a former aide to Vice President Al Gore.

As for Obama's ability for new legislative achievements, Bennett, a senior vice president at the Democratic leaning Third Way, said: “The question was whether that window was ever open. This Congress is so unremittingly hostile that it just isn't clear that he ever had a chance to do big legislative things in this term.''