Recent polls suggest 80% of the public wants President Obama to seek Congressional approval before engaging in military action in Syria.
In 2007, Senator Obama wrote in the Boston Globe:
"The President does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation."
In 2007, Senator Biden stated on MSNBC:
"...the president HAS NO CONSTITUTIONAL AUTHORITY to take this country to war against a country of 70 million people unless we're attacked or unless there is proof that we are about to be attacked. And if he does, I would move to impeach him."
Abide by the convictions that helped get you elected. Seek Congressional approval before taking military action in Syria.