538 says that Obama has a 65% chance of winning.
Honestly there are so many models that contradict each other that you may as well flip a coin.
Edited:
Not really. Ever since the presidents since Truman started claiming their title of "Commander in Chief" lets them do what ever they wish (and Congress just decided to go with it for god fuck knows why), all the president has to do is send troops in to a country.
If the people don't like it, if Congress doesn't like it....well, kinda too late, can't just pull everyone out and say, "Whoops, sorry about that, honestly didn't mean to wreck everything" and forget about it.
If I remember correctly, Congress gave the president [idiotically] 60 or 90 days of doing what ever before Congress has to say, "Okay you're allowed [to keep fighting a war, not that we would be able to say otherwise now anyway]"
On one hand, the President has way too much power to wage wars.
On the other hand, Congress is so slow and dysfunctional that we would have never gone to help Libya, which would have been disastrous for the rebellion. Not fatal, since many other countries helped, but still a big setback for them.