Suzy Khimm, Josh Barro and Dylan Matthews have already done excellent work breaking down the "six studies" that Mitt Romney says prove his tax plan adds up. Here's the short version:

• Four of them are blog posts or op-eds. As Barro writes, "I'm not hating — I blog for a living — but I don't generally describe my posts as 'studies.' "

• Two of them are the same study by the same guy. The Romney campaign lists Martin Feldstein's op-ed as a study and then lists Martin Feldstein's blog post defending his op-ed as a study. Foul.

• Some of them actually show Romney's math doesn't add up. Feldstein's two entries, for instance, say Romney's plan will increase taxes on people making between $100,000 and $200,000. To Feldstein, those folks aren't middle class. But Romney says they are middle class. As such, Feldstein's study shows that Romney is actually raising taxes on the middle class.

I don't have much to add to what Khimm, Barro or Matthews have written on the substance of these studies. But it's worth pointing out the brazenness of the Romney campaign's talking point. They know four of their six studies aren't, even in the loosest definition of the term, "studies." They know two of the four are duplicates. They know three of the six define "high income" as above $100,000, and their results thus imply a tax increase on taxpayers their candidate has publicly defined as middle class. 

And yet they keep saying it. Because why not? How can any voter tell the difference between studies that add up and studies that don't? 

Romney said this pretty explicitly during the first presidential debate. 

There are six other studies that looked at the study you describe and say it's completely wrong. I saw a study that came out today that said you're going to raise taxes by $3,000 to $4,000 on middle-income families. There are all these studies out there.

Note that Romney doesn't even try to defend the $3,000 to $4,000 tax cut claim, which is ridiculous. Instead, he uses it as evidence that voters should ignore all of these claims. "There are all these studies out there," Romney says. Like, you've got your truth, and I've got mine, man. It's the most postmodern thing I've seen since I was an undergraduate at UC Santa Cruz.

This is how the Romney campaign has treated numbers in general. The evidence behind their "12 million jobs" claim is a joke. Their white paper and subsequent op-ed on the economy misrepresented almost every economist it mentioned. Their tax and spending plans are missing pretty much all of the relevant information. The standards behind the talking points and policy proposals the campaign releases are insultingly low. 

But the theory is clear. What matters isn't whether the Romney campaign's numbers add up. It's whether they've got a bunch of numbers to throw at the Obama campaign's numbers, and at the analyses from independent experts. "There are all these studies out there." And who knows? Maybe they're right. Maybe all voters take away is that there are all these studies out there, and the only ones you should trust are the ones you agree with. But I hope not. I really hope not.