True, 10% seems like a lot, but someone needs to figure out what the rate would be for the this demographic of income earners without respect to political affiliation. It’s possible that these donors are in such a tax bracket as to make them subject to a higher than average audit rate.
True. This has all of the preliminary indications of a game-changing scandal, but we need much more information. What was the sample size? What was the "official" reason for the audits (e.g., were they "random," or were there red-flags in the returns)? What was the error rate in the audits vs. a typical audit?
One big question that comes to mind is whether the donors in question attempted to deduct their contributions - most tea party groups (and analogous groups on the left) are organized as 501(c)(4) organizations (or, in this case, were seeking such organization). Unlike donations to 501(c)(3) organizations, donations to 501(c)(4) groups are generally not deductible for the taxpayer. A surprising number of people do not know that, and a surprising number of people do their own taxes without consulting an accountant.