Seven Democrats and three Republicans supported the measure, while two Democrats and five Republicans opposed. Among Republicans, opposition came from lawmakers with the closest ties to tea party activists, including Paul and Florida Sen. Marco Rubio, both presidential aspirants.
Among Democrats, Kerry's replacement in the Senate, Sen. Ed Markey, D-Mass., voted "present" after expressing misgivings.
In his comments in Sweden, the president sought to shift the onus for responding to Assad to Congress and the world at large. "I didn't set a red line. The world set a red line" with a treaty banning the use of chemical weapons. He added that "Congress set a red line" when it passed legislation a decade ago demanding Syria stop production of weapons of mass destruction.
His comments drew a disbelieving response from one Republican back home.
"He needs to go back and read his quote," Sen. Saxby Chambliss of Georgia said, referring to a comment the president made slightly more than a year ago. On Aug. 20, 2012, Obama said, "We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized. ... "That would change my calculus" about military action, he added at the time.
Elsewhere on Wednesday:
— In Syria, al-Qaida-linked rebels were said to have launched an assault on a government-held Christian mountain village in the densely populated western part of the country, and there was new fighting near Damascus as well.
— In Rome, Pope Francis underscored Vatican opposition to threatened military strikes against Syria, urging Catholics and non-Catholics alike to take part in a day of fasting and prayer for peace on Saturday.
— In France, Prime Minister Jean-Marc Ayrault told parliament that failure to take action would allow Assad to launch more chemical attacks.
By his country's intelligence, the Syrian has an abundance of material. Sen. Richard Durbin, D-Ill., citing a French estimate, said at the Senate meeting that Assad has an estimated 1,000 tons of chemical weapons material and "may be in the chemical weapons world a superpower."
Kerry said Assad had used chemical weapons 11 times but until the most recent attack the president did not have a "compelling" enough case to push for a U.S. military response.
Few if any members of Congress dispute the administration's claim that Assad was responsible for the attack, and lawmakers in both parties appear far more focused on determining how they should respond.
Gaveling the House committee hearing to order, Rep. Ed Royce, R-Calif., said that while it would be important to deter the use of chemical weapons by Assad and others, there remained many unanswered questions, including what the U.S. would do if Assad retaliated.
"The administration's Syria policy doesn't build confidence," he said.
In a letter to her rank and file, Democratic Leader Nancy Pelosi of California said she had received suggestions for legislation in the House "to add language to prevent boots on the ground, to tie the authorization more closely to the use of chemical weapons and to address concerns about an open-ended timetable."
Associated Press writers Julie Pace and Josh Lederman in Sweden and Bradley Klapper, Alan Fram, Deb Riechmann, Kimberly Dozier, Lolita Baldor and Andrew Taylor in Washington contributed to this story.
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