Unlike in the case of Libya, Obama has decided to seek approval from Congress before going to war with Syria. But he and Kerry have made it clear that they think consulting with the legislature, the only branch of government authorized by the Constitution to declare war, is optional.
"I have the authority to carry out this military action without specific congressional authorization," Obama asserted on Saturday. "The president of the United States has the right to take this action," Kerry told ABC News the next day. "(He) doesn't have to go to Congress."
Obama took a different position on the president's powers before he started wielding them. "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," he told the Boston Globe in December 2007.
That was Obama's written response to a questionnaire about executive power, so he had time to reflect on the implications of those words. Among them: If Congress declines to approve the use of military force against Syria when it votes on the question next week, Obama does not have the constitutional authority to proceed with an attack anyway.
Kerry, who appeared on several Sunday morning talk shows over the weekend, was repeatedly asked what his boss will do if Congress rejects military action against Syria. He dodged the question every time.