Candidate Obama vs. President Obama on presidential power

After listening to President Obama’s speech this afternoon regarding Syria, I read an article in the newspaper. I imagine the national pundits have already made note of the contradiction I discovered, but I don’t listen to a lot of talk radio, so it struck me as a profound about-face.

Here’s what Candidate Obama told the Boston Globe in December 2007 (which was quoted in an AP story I read in the Journal Star this morning):

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.

But today, President Obama had something different to say (emphasis mine):

Now, after careful deliberation, I have decided that the United States should take military action against Syrian regime targets. […] Yet, while I believe I have the authority to carry out this military action without specific congressional authorization, I know that the country will be stronger if we take this course, and our actions will be even more effective.

So Candidate Obama believed the President does not have the power to authorize military action unilaterally, but President Obama does believe the President has the authority to take military action unilaterally. What has changed since 2007? Well, obviously, Obama is now President! It appears that the power of the Presidency has changed Obama’s mind.