Obama lines up key support in Congress for Syria attack WASHINGTON - Key lawmakers in both parties endorsed President Obama's call for a punitive strike on Syria, giving momentum to his drive to win authorization from Congress as it began the most momentous debate on the use of military force since the 2002 run-up to the war in Iraq. Although members of Congress remain deeply split and polls indicate Americans oppose military action, Obama on Tuesday won the backing of the two top House Republicans, Speaker John A. Boehner of Ohio and Majority Leader Eric Cantor of Virginia. He also picked up the support of the No. 2 House Democrat, Steny H. Hoyer of Maryland; House Minority Leader Nancy Pelosi (D-San Francisco) was already on board. Late Tuesday, the top Democrat and Republican on the Senate Foreign Relations Committee agreed on language authorizing U.S. military action against Syria for its alleged use of chemical weapons in the suburbs of Damascus, while ruling out the commitment of U.S. ground forces and limiting the window for an attack to 90 days. A committee vote could come as early as Wednesday. Earlier, Secretary of State John F. Kerry, along with Defense Secretary Chuck Hagel and the chairman of the Joint Chiefs of Staff, had sought to dispel the concern of some committee members that, as with Iraq, the U.S. was at risk of acting on flawed or exaggerated intelligence, or that the U.S. could be drawn more deeply into Syria's civil war. This is not the time for armchair isolationism. This is not the time to be spectators to slaughter," Kerry said. Obama took one of the biggest gambles of his presidency Saturday when he announced he would seek Congress' blessing for military action in hope of bolstering the limited foreign and domestic support for the mission. Substantial risk remains that rank-and-file lawmakers in the House, who sense the hostility of many Americans to more U.S. military action in the Middle East, could break with their leadership. But Boehner urged Republican House members, usually antagonistic toward Obama, to support him because "this is something that the United States, as a country, needs to do." He called Syrian President Bashar Assad's alleged attack with sarin gas, which the U.S. says killed more than 1,400 people on Aug. 21, a "barbarous act." Obama called for Congress to act promptly. What we are envisioning is something limited. It is something proportional," he said in brief comments before meeting with legislators. It will degrade Assad's capabilities. At the same time, we have a broader strategy that will allow us to upgrade the capabilities of the opposition. The language crafted by the Senate Foreign Relations Committee chairman, Robert Menendez (D-N.J.) and the committee's leading Republican, Bob Corker of Tennessee, calls for the use of force "in a limited and tailored manner" against military targets in Syria in response to the government's use of "weapons of mass destruction." Two leaders of the Senate's hawk faction, John McCain (R-Ariz.) and Lindsey Graham (R-S.C.), also argued on television news shows in favor of a strike, although they remain critical of how Obama has handled the Syrian civil war. 3 House lawmakers from both parties, Rep. Kevin McCarthy (R-Bakersfield) and Rep. James E. Clyburn (D-S.C.), remain undecided. So do most lawmakers, who are still weighing the policy merits and the political risks of a vote that may be deeply unpopular whichever way they decide. Two polls released Tuesday, from the Pew Research Center and Washington Post-ABC News, found that Americans remain opposed to U.S. military action in Syria. Yet key members and aides said Boehner's announcement provided at least a temporary momentum swing from Saturday, when many in Congress were predicting that the support Obama sought was not there. Lawmakers lining up with Obama said that if the United States did not seek to deter chemical weapons use, it would embolden Assad and his allies in Iran; hurt America's standing around the world; and put U.S. allies such as Israel, Jordan and Turkey at risk of such attacks. The Boehner-Cantor decision "is a game-changer for the House vote, and far more important than McCain and Graham, who lead a small minority seeking greater military involvement," said a senior Senate aide who declined to be identified because he was not authorized to speak publicly. The aide noted that a number of traditional hawks, such as Sen. Mark Steven Kirk (R-Ill.), were also lining up with Obama in favor of a limited strike. Speaking Tuesday before the Senate committee, at the first congressional hearing on the issue, Kerry, Hagel and Joint Chiefs Chairman Gen. Martin Dempsey said inaction was unacceptable. "The risk of not acting is greater than the risk of acting," said Kerry, a former chairman of the committee. He said he and Hagel, who had been in the Senate for the Iraq vote a decade ago, "are especially sensitive ... to never again asking any member of Congress to take a vote on faulty intelligence. And that is why our intelligence community has scrubbed and rescrubbed the evidence. Kerry said Assad had been responsible for a series of chemical weapons attacks numbering "in the teens," which suggests the Syrian military has employed them far more than has been publicly known. Administration officials were unable to provide any immediate elaboration. Obama's position also drew an expression of public support from former Secretary of State Hillary Rodham Clinton, a possible 2016 Democratic presidential candidate, who had remained silent on the issue.