Over the past week or so, some of the more devoted (and blinkered) supporters of the IRS have tried to make the case that the agency's targeting of conservative and tea party groups was all a big mistake and anyway, it's the GOP's fault.

The latest example of this is the Brookings Institution's  Henry J. Aaron who argued that one of the things that caused the targeting was a lack of funding for the IRS.

Others have made a similar argument, that the IRS agents—now numbering more than 80—requested more paperwork, filed more documentation and did overall more work because they were undermanned and underpaid. This argument doesn't pass the laugh test. Normal people know when you're swamped with work, you don't intentionally make more work for yourself. Instead, you choose some things that you just let slide. That's obviously not what happened here.

Aaron makes a slightly different argument: He claims that a lack of funding for the IRS led to a dearth of training and oversight.

The toll from short-changing the IRS is not just lost revenue. When resources are so meager and the return to enforcement is so high, administrators are loath to divert budget and staff from chasing evaders to staff training and oversight. It would be absurd to say that the administrative abuses now so much in the news are caused by meager budgets—after all, real live people who should have known better did what was done and real live supervisors failed to stop them from doing it. But a major reason why training and oversight were missing is that short-sighted, penny-pinching members of Congress deprived the IRS of enough money and staff to do what Congress asked them to do.

Unfortunately for Aaron, as more and more details come out, it's clear that there was no lack of oversight or training. Contrary to early reports, this wasn't a couple of rogue agents in Cincinnati doing this on their own. The supervisors, the ones who would do the training that Aaron says a cheapskate Congress wouldn't give them money to do, were the ones directing the harassment.

And then came this bit of inconvenient news for Aaron's theory: The IRS spent about $50 million to hold 220 conferences for employees between 2010 and 2012 when the targeting was going on. Doesn't sound like a lack of training or supervision was going on to me.

There's no excuse for the IRS's behavior. None. People like Aaron would do well to hold their tongues, because the scandal shows every sign that it will get worse before it gets better.