Holder was, more than likely, acting under direct orders from Idi Obama.
After Holder's past actions with regard to "gun control" and his statements regarding the same: Eric Holder in 1995: We have to brainwash people against guns. Holder probably devised the scheme using the "we can blame Bush if it blows up, cause he did something similar" and presented it to Barack "He Who Cannot Be Blamed" and received the "Screw the Constitution" seal of approval from his Assholiness..
Here's an article from February 2009 which illustrates Obama's/Holder's mindset for masterminding the 'Fast & Furious' plan:
http://abcnews.go.com/Politics/story?id=6960824&page=1#.T-tP4lK8h5E