This image of Barack and Michelle Obama made double history tonight. First, it anchored the most popular tweet in history. Then, it broke records on Facebook. With more than 2.2 million likes as of this writing, the simple, poignant picture -- a husband and wife, embracing -- is now the most-liked Facebook photo in history.
Update, 8:20 a.m.: The image's current like status? Nearly 3 million.