Look at the charts in your own link, spanning 2007-17. Audit rates were increasing under GWB, then plummeted over the course of the Obama administration into 2017.
Otherwise it's just a very baseless claim about an otherwise well documented problem about a few IRS bureaucrats. ( https://en.wikipedia.org/wiki/IRS_targeting_controversy )
I argue we should know more about this but don't because "oh, it's fake." ... And because of the deleted evidence.
http://www.breitbart.com/irs/2017/03/13/fitton-obama-irs-sca...