To improve its odds, the White House is enlisting virtually every senior official from the president on down. In addition to members of Congress, it is reaching out to Jewish groups, Arab-Americans, left-leaning think tanks and even officials from the George W. Bush administration, some of whom are acting as surrogates. It is also getting help from the nation’s most powerful pro-Israel group, the American Israel Public Affairs Committee, which is mounting its own campaign for military action…

Among the most visible surrogates could be Hillary Rodham Clinton, Mr. Obama’s former secretary of state, who aides say is likely to address Syria at one or both of two events this week: a previously scheduled visit to the White House on Monday to promote wildlife conservation, and a speech the next day in Philadelphia.

The White House is also putting officials, including the president, before audiences and television cameras. Mr. Obama will tape interviews on Monday with ABC, CBS, NBC, Fox, PBS and CNN. Mr. McDonough will appear on all five Sunday news programs, and on Monday the national security adviser, Susan E. Rice, will address the New America Foundation, a nonpartisan public policy institute.

The last time the White House lobbied this intensively on a single issue was the 2009 health care law. But unlike that battle, which was largely pitched to the Democratic ranks, the White House this time is also appealing to Republicans. Administration officials note that in private conversations, lawmakers repeatedly asked to have their voices heard on Syria.