That tiresome cliche "throwing [some specific person] under the bus" has spread like a virus. According to Wikipedia, it emerged in sports journalism in 2004 and became even more prevalent during media coverage of the 2008 presidential election cycle. The site also indicates that the expression's origins could date back to the late 1980s or early 1990s.
This CNN snippet seems to suggest that the presidential timeline doesn't match that of Attorney General Eric Holder in regard to the Fast and Furious scandal.
In the following clip, DOJ whistleblower J. Christian Adams discusses the corruption in Holder's radicalized Justice Department concerning Fast and Furious along with its unwillingness to prosecute voter intimidation and vote fraud.