[WS:] They may or may not, but I see no reason why they should. If they voted no, this would weaken O and strengthen the congress - so they have a good reason to vote no. As far as public opinion is concerned, most polls I've seen show strong opposition, but that of course does not mean much.
I think that his move was a sign of weakness, lack of vision, and being cornered than political genius. A smarter view would be supplying the rebels: it would silence most criticism you mention, allowed him greater flexibility, and would be rather safe politically. If this thing gets out of control - which is quite possible if the Russians keep their promise to help Assad - he would face a far greater blowback than Bush got for Iraq.
O may not face re election, as Carter did, but if he becomes a lame duck he has as much to lose - e.g. the battle over PPACA which his opponents are anxious to undercut.
In any case, let's wait and see what happens.
-- Wojtek
"An anarchist is a neoliberal without money."