Operation Fast and Furious, Holder in contempt for coverup?

Democrats are saying the potential Congressional investigation and upcoming  vote on holding AG Holder in contempt is a "witch hunt." This is the usual cry of both Democratic and Republican stalwarts whenever someone goes after their President.  "Sunshine is the best disinfectant." However, the Obama  adminsitration has not be truthful over the course of the investigation.  Whatever happened to Obama's promise for a more open government.  Another campaign promise bites the dust once the promisor gets in office.  The first lie (?) perhaps came in 2010:

"What's the controversy over the Justice Department's Feb. 4, 2010 letter to Sen. Grassley?

In its earliest response to Sen. Grassley's questions about the gunwalking operation, the Justice Department sent a letter that contained inaccurate information. The letter, signed by Assistant Attorney General Ronald Weich, stated that ATF never "knowingly allowed the sale of assault weapons to a straw purchaser who then transported them into Mexico." Ten months later, the Justice Department withdrew the letter acknowledging that it contained inaccuracies. In April 2012, Weich announced his intention to resign from the Justice Department to become dean of the University of Baltimore Law School. Documents subpoenaed by the House Oversight Committee, but not turned over, include Justice Department communications after the Feb. 4, 2010 letter leading up to the Dec. 2010 retraction of the inaccurate letter. Republicans in Congress want to see who-knew-when that the Feb. 4 assertion denying gunwalking was false, and why it took ten months for the administration's retraction."

For more from CBS on the controversy and the source of this quote see this article.