As part of his critique of Herman Cain’s absurd “9-9-9” tax plan, Mitt Romney said in last night’s debate, “I want to reduce taxes on middle-income families.”

It was a throw-away line, mentioned in passing. But it’s important to realize what Romney claims to “want” is not even close to what Romney actually intends to do.

In fact, there’s no real ambiguity here. The apparent Republican frontrunner has already said he wants to see middle-class taxes go up right away, having endorsed an increase in payroll taxes in 2012. Romney has also backed higher federal income taxes on lower- and middle-income earners for the foreseeable future. He’s been surprisingly explicit on this, recently telling voters, “I think it’s a real problem when you have half of Americans, almost half of Americans, that are not paying income tax.”

Of course, those who aren’t paying income taxes include a fairly narrow group of people: lower- and middle-income workers who fall below the tax threshold; the unemployed; students, and retirees. Romney thinks it’s a “real problem” that they’re not paying federal income taxes — and it’s a problem he intends to fix by raising their taxes.

But, the former governor says, that’s only part of the picture. Sure, Romney will raise middle-class income taxes, but he also intends to give the middle class a capital-gains tax break.

Under Romney’s plan, those making less than $200,000 a year would see their capital gains taxes eliminated entirely. And what’s wrong with that? Pat Garofalo explained:

Romney may think he focused his tax cut on the middle-class, but according to a ThinkProgress analysis of Tax Policy Center data, nearly three-fourths of households that make $200,000 or less annually would get literally nothing from Romney’s tax cut, due to the simple fact that most of those households have no capital gains income

To be exact, 73.9 percent of the households upon which Romney “focused” his tax cut will see zero benefit from it. […]

For families making between $40,000 and $50,000 annually, Romney’s tax cut comes out to a whopping $216 per year. Meanwhile, the payroll tax cut enacted by the Obama administration in 2011, which Romney derided as a “temporary little Band-Aid,” gave those same households a tax cut of $800 to $1,000.

Romney also, incidentally, wants massive tax breaks for the wealthy and corporations.

“I want to reduce taxes on middle-income families”? What Romney “wants” is irrelevant.

To be sure, there are some who might argue that middle-class taxes should go up, and it’s a subject worthy of debate. The problem here is that Romney just isn’t telling the truth about his own agenda. If he intends to raise middle-class taxes, and his own plan suggests that he does, Romney should prepared to defend his agenda.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.