Update - Breitbart has a post by Joel B. Pollak wondering if the deliberate small plane crash into the Austin, Tx. IRS offices wasn't the trigger for the "let's get the Tea Party" attacks. The crash happened on Feb 18, 2010. Speculative, yes, but Obama's meeting with the IRS union boss happened less than two weeks later, and the attacks began the next day.
Pundette has a link to this story at American Spectator, about a meeting between the head of the IRS' employee's union and Obama the day before the IRS started messing with "... the Tea Party and other conservative groups..." So it thus appears that the IRS' marching orders, while coming from the very, very tippy-top, were actually communicated from the "side", instead of through the legal chain-of-command.
The story at the links is loading very slowly, if at all. I suspect that's because it is linked on both Drudge and Instapundit. (5-20-2013)