Donald Trump, as expected, stole the show at Thursday's Republican presidential debate. Less dramatic, but more profound, observers believe, was that Facebook co-sponsored the event with Fox News.
The social network's high-profile participation spotlights a trend that has been building for years: the ascendancy of social media in electoral politics and the decreasing relevance of traditional television.
Videos of Trump dissing people including Rosie O'Donnell and his fellow candidates while calling politicians "stupid" quickly spread to millions of Facebook users and other social channels online, foreshadowing social media's critical role in the long road to Election Day.