On the pro side, those who support intervention tend to agree with President Obama's case that military action is necessary to deter the use of chemical weapons. But those voices are a distinct minority. And only about 4 percent* of those responding to the poll say that intervention is necessary to "protect U.S. interests":
Do these surveys matter at all? Joshua Tucker, a political scientist at New York University, is skeptical that national polls will sway Congress one way or the other at this point:
I think public opinion mattered insofar as it may have played a role in getting Obama to seek Congressional approval in the first place — although personally I think the lost vote by Cameron in the UK was probably more important — but at this point the ball is probably in Congress’s court. ...The Senate is likely going to vote to approve in any case, and the House dynamics are going to follow district level concerns more than national ones.
Still, he points out, the consequences of the vote itself could well reverberate down the road, such as in primary elections for individual members.
* That is, 11 percent out of the 36 percent who actually support intervention, or 4 percent of all respondents.