Yesterday morning, Washington Post blogger and de facto Mitt Romney surrogate Jennifer Rubin published a lengthy critique of the Tax Policy Center's recent report on Romney's tax plan. The TPC described Romney's goal of a revenue-neutral plan that does not raise taxes on lower income workers as “not mathematically possible.” Rubin rejected the Tax Policy Center's analysis, calling the group both “left-leaning” and “very partisan.” That's a far cry, however, from last October when the TPC released a report critiquing the tax plan of Romney's then-opponent Herman Cain, and Rubin touted the “independent” group's analysis as proof that "Herman Cain's math is wrong."

Here's Rubin on October 13, 2011, showing the TPC some love:

Herman Cain certainly has an issue. He's put all his chips on 9-9-9 and brazenly dismissed critics as know-nothings or misrepresenters of his plan. It's become obvious, however, that it is he who is trying to pull a fast on. First Read discovers what many of us have: The plan is highly regressive. Yet another independent set of eyes has looked at Cain's plan now:

The nonpartisan Tax Policy Center is readying a report on Cain's plan, though it is waiting for more details from the campaign. But it has come to some conclusions already.

Cain's plan “cuts taxes for the rich and raises taxes on the poor,” Roberton Williams, a senior fellow at the center, tells First Read. He added that it would create a “much more regressive tax system.”

The plan would represent a “major tax cut” for the rich and raise taxes “substantially” on the poor and middle class, Williams said. “Given that a big chunk doesn't pay any income tax, this would be a big tax increase on people at bottom end. At the top end, the opposite happens.”

Fast forward to yesterday, as Rubin once again took on a TPC report on a detail-light tax plan from a Republican presidential candidate:

My colleague Greg Sargent insists that by Mitt Romney saying “The president's ad saying I'm gonna raise taxes on the middle class? That's patently, simply false,” Romney is admitting his plan won't be revenue neutral. Not only does Romney not say that, but that very broad proposition is not supported by the left-leaning Tax Policy Center study released last week.

[...]

This is not, by the way, to say that the plan is politically attainable. It is just to say that the very partisan Tax Policy Center didn't prove, as its media advocates have said, that it is “impossible” for Romney's plan to be revenue neutral and maintain progressivity.

What a difference a candidate can make!

The remainder of Rubin's post is devoted to explaining why it's not the responsibility of the presidential candidate to release more specifics regarding his tax plan (“Romney's plan is conceptual, not written in legislative detail”). Rather, according to Rubin, the onus is on groups like the TPC to do a better job filling in the massive gaps Romney refuses to:

In sum, if you assume a bunch of stuff, include a bunch of stuff that Romney never said and then leave out all of Romney's other policies, then Romney's plan doesn't work. TPC does this in the guise of “assumptions,” which President Obama's ads and pro-Obama pundits leave out. (This is not unlike the Obama team's “outsourcing” gambit, in which a much more limited factual assertion gets used for a much broader, unsupported political assertion.)

But perhaps the best part is that after slamming the TPC's analysis as “very partisan,” she praised herself for her own analysis of the TPC report, which she developed with a little assistance:

It turned out I was more right than I knew when I began digging. With help from a certified public accountant specializing in high-net-worth individuals and from a conservative tax analyst at an advocacy group (with no connection to the Romney campaign), here is what I found.

Don't trust the left-leaning Tax Policy Center, but by all means take Jennifer Rubin's “conservative tax analyst” who works “at an advocacy group” at his/her word. They're not connected to the campaign, so it's all good.