Even if I generally trust Obama's judgement, I have no reason to trust the intel he is receiving.
Who is feeding the administration's intelligence on the ground? Is it the rebel groups? Is it the Saudis and the Turks? Is it a bunch of contractors in the region working for companies that have a lot to gain from a conflict? Because they are all suspect. Everyone has an ulterior motive in this. The Saudis want us doing their dirty work for them. The contractors want to get paid, sequestration be damned.
And at the same time, I have a tough time trusting the judgement of several of his cabinet members. Kerry strikes me as a decent human being and I don't distrust his motives here, but I can't help but remembering that he was "fooled" once over ten years ago on one of this nation's biggest foreign policy decisions.
If I were a congressman, I'd say sorry Mr. President, yes I agree the use of chemical weapons is disturbing, but without any compelling evidence as to whom is using them, what the end outcome should be (the basic efficacy of dropping some cruise missiles), and the potential risk of getting caught in or making worse an already horrific civil war - I would have to vote NAY.