Polls tend to show that military action against Syria is unpopular with the broader American public. And the latest Gallup poll is no different: 51 percent of respondents are against the idea; 36 percent are in favor.

Gallup also breaks down the reasons given for opposing military action. The most common reasons are "None of our business" or "Don't need to be involved in another war":

Note that few respondents bring up the question of whether there's sufficient evidence to go to war. That jibes with a recent CNN poll suggesting that Americans overwhelmingly believe Bashar Assad's government used chemical weapons on civilians — but are opposed to a U.S. military response anyway.

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.