The Constitution means nothing to Democrats and Republicans:
The U.S. and its coalition partners have thus far carried out hundreds of airstrikes in Iraq and Syria in an effort to destroy the Islamic State. Some members of the coalition, most recently the UK, have committed to airstrikes against targets in Iraq, while others have sent weapons and trained personnel to assist moderate rebels in Syria. Meanwhile, the Islamic State, also known as ISIS or ISIL, continues to recruit members with violent ideologies and is attempting to expand its control over large swaths of Iraq and Syria.
Yet the Obama administration has maintained that the U.S. is not "at war." Indeed, the country hasn't officially declared war on any nation or organization since entering World War II over 70 years ago. Of course, that doesn't mean the U.S. hasn't engaged in a number of extended military operations, including the widely criticized war in Iraq. Administration officials may be wary of potential parallels to that conflict as they consider how to label their campaign against the Islamic State.