That's some trendline in the Pew poll question about Syria. The pollster has been asking people, for 15 months, whether they're on board with sending aid to Syrian rebel groups. What started as a +34-point margin for "no" is now a +50 margin for no.
March 2012 was the escalation period that drove up American awareness of the situation Syria. December 2012 was a period of success for rebel groups—and more definitive criticism from the Obama administration. June 2013? Why, that's when the administration meandered toward a larger committment. And people don't want it.
Neither does the White House! If you parse what aides have been saying about the new aid, they don't even talk of a U.S.-boosted victory. They talk about an "even playing field" and a "settlement." How far we've traveled from 2003, when it was perfectly ordinary to hear the Bush administration chastise Syria for sending arms into Iraq and to let the impression of a "next war" hang in the air.