What was the most-tweeted moment of the 2012 campaign?

In an election in which social media came into its own, a photograph of Barack and Michelle Obama hugging with the caption “four more years” was tweeted by the campaign just after midnight on election night and quickly became the most retweeted Twitter post ever. The photo was retweeted a record 226,000 times in the first 20 minutes alone. When it was uploaded to Facebook, the image set a record for most “likes.”