How important is it for Congress to pass an authorization on the fight against the Islamic state?

Considering our very partisanly-divided country, I feel it’s very important for Congress, whose responsibility it is to declare war, to step up and authorize action against ISIL wherever they roam.  Public opinion waxes and wanes on our involvement in any Mid-East turmoil.  “In 2013, Congress balked at Obama’s request to authorize strikes in Syria and never held a vote”,  yet it was deemed “Obama’s inability to act” by the Obama-haters, who want to blame him for everything that happens in the remotest corners of the globe.  He’s either doing nothing or over-stepping his bounds of authority according to the haters propaganda.  The military campaign against ISIL actually began months ago; Obama has deemed the “current mission legally justified under the 2002 authorization President George W. Bush used to start the Iraq war”.  But Republicans shouldn’t get to use this as a tool against our President; we need to speak with ONE VOICE AGAINST TERRORISM!   And the Saudis need to do their fair share in the region!