Via ABC News:

ABC News has obtained an ad the RNC made last fall and approved to air in the final weeks of the presidential campaign.  The ad begins with a replay of Hillary Clinton’s famous “3 a.m. phone call” commercial from the 2008 campaign and then cuts to video of the burning U.S. consulate in Benghazi Libya. [...]

A source familiar with the creation of the ad says the RNC leadership approved the ad but it was scrapped at the last minute because of objections from the Romney campaign, which was concerned the ad would distract from Romney’s efforts to focus on the economy.