As President Obama weighs a military response to what he concludes was a chemical attack recently launched by the Syrian government on its citizens, a growing chorus of lawmakers is pressing him to seek congressional approval before using force.

Candidate Obama would probably have been right there with them.

(Carolyn Kaster/AP)

In a 2007 question-and-answer session with the Boston Globe that's received a lot of attention in recent days, then-presidential candidate Obama said that the president isn't empowered to order a military strike when the country is not under an immediate threat.

"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," the senator from Illinois said in response to a question about whether the president would have the authority to bomb Iran without approval from Congress.

"As Commander-in-Chief," Obama said, "the President does have a duty to protect and defend the United States. In instances of self-defense, the President would be within his constitutional authority to act before advising Congress or seeking its consent. History has shown us time and again, however, that military action is most successful when it is authorized and supported by the Legislative branch. It is always preferable to have the informed consent of Congress prior to any military action."

More than 170 members of Congress from both parties have signed letters asking the administration to pursue congressional approval before taking U.S. military action. Administration officials planned to brief select lawmakers on the situation in Syria later Thursday. The White House said it has not finalized a decision on military involvement in that crisis. And White House officials have not said whether the president intends to first seek congressional approval.

Some lawmakers, such as Sen. John McCain (R-Ariz.) and Rep. Peter King (R-N.Y.), have argued that the president does not need congressional approval in this case. Still, it is in Obama's interest to consult with Congress, they've argued.

This isn't the first time the question has surfaced over whether or how Obama must loop in Congress regarding U.S. military action. Rep. Scott Rigell (R-Va.), who penned a letter on Syria that carries the signatures of more than a 100 lawmakers, criticized Obama's  conclusion in 2011 that he did not have to have approval from Congress for military involvement in Libya.

If Obama opts not to pursue congressional approval for military action against Syria, look for critics to point to those 2007 comments he made -- when he was a U.S. senator -- about looping in lawmakers before making a decision.