President Barack Obama and Mitt Romney are in a battle for the trust of the middle class. The group might be hard to define, but most Americans say they are part of it, and many swing voters fall into it. Accordingly, both camps roll out the term frequently in their campaign ads.



The Obama campaign has a new ad called "Pay the bills." It features a woman named Christie who describes a very ordinary life:

Christie: "I do the laundry. I pay the bills. I make sure my kids are fed and rested and healthy."

Announcer: "Moms like Christie would be stretched even more under Mitt Romney. To fund his tax cuts for millionaires, Romney could take away middle-class deductions for child care, mortgages and college tuition."

Christie: "Mitt Romney? He’s so focused on big business, and tax cuts for the wealthy. It seems like his answers to middle-class America is just ‘tough luck.’"

Democrats have been attacking Romney’s tax plan since the summer. It was a favored target during the Democratic convention.



The claim in this new ad is more specific than some others we’ve looked at. Here, we’ll examine the premise that Romney’s plan could take away middle-class deductions for child care, mortgages and college tuition.



To begin with, we’ll note that "could" is a very open-ended word. Many things "could" happen but that doesn’t mean they are likely to. The ad’s focus on some theoretical possibility should be contrasted against Romney’s promise that he will not raise taxes on the middle class or touch their tax deductions. This came up when Romney was asked about a study that challenged his proposals.



"They made an assumption that I would reduce the home mortgage-interest deduction," Romney said in an interview with Fortune. "I will not do that for middle-income taxpayers."



Romney specifically said he would "preserve tax preferences for middle-income taxpayers such as homeownership, charitable giving and health care."



Romney’s problem is that he has set many goals for his plan, and they tend to conflict with each other. It is difficult, for example, to cut rates, keep tax collections the same, and keep the tax burden the same across all income groups.



Briefly put, Romney would lower tax rates across the board and make up the difference by taxing income that isn’t taxed today. This is called broadening the tax base, and the biggest pots of money there are found in the deductions for home mortgages, charitable donations, state and local taxes and employer-paid health insurance benefits.



Romney has said he would change the rules on tax deductions on higher income households, but he hasn’t provided enough details for any analyst to specifically predict the consequences of his ideas.



The challenge of tinkering with deductions



The Obama campaign backs up its claim by citing the work of the Tax Policy Center, a joint project of the Urban Institute and the Brookings Institution. The collaboration includes analysts with past ties to both political parties. The Tax Policy Center reported that in order for Romney to keep some of his main revenue and tax rate goals, he would need to eat into the tax deductions enjoyed by some middle-class households.



Does it follow that Romney’s plan would "take away" those deductions? William Gale, one of the report’s authors, said one should interpret the study more carefully.



"It is accurate to say that it is not inconsistent with our study to say that those items could be on the block for at least some middle-income earners," Gale said. "But that’s a lot of wiggle room."



In other words, the ad speaks with more certainty and in more sweeping terms than did the underlying study the campaign cites. Gale’s study did not say that all middle-class households would be affected; it found that those making more money would be. In addition, it did not say the outcome was inevitable. Rather, it found that middle-class taxes would go up if Romney stuck to every other goal in his plan. However, if he was flexible on one of the goals, then the middle class could go untouched.



On the other hand, a study cited by Romney in support of his plan found that the numbers worked when deductions were reduced for households making $100,000 and up. Romney himself has said that would include people who he would characterize as middle class.



Another Tax Policy Center report cited by the campaign cast doubt on a core premise of Romney’s plan. The report did not assess Romney's plan directly but noted that reducing the most widely used deductions might not produce the revenues needed to offset the ones lost through rate cuts.



It also cautioned that many scenarios would raise effective rates on middle-income earners, while giving a tax break to people making more. However, it said the numbers could work if lawmakers in both parties were willing to make enough compromises on what they will and will not tax.



"It is possible to maintain revenues in the face of large marginal tax rate cuts by paring back tax expenditures, but it would be very difficult," the report said. "And the task becomes much harder if another objective is to maintain the progressivity of the federal income tax."



The report authors acknowledge that there is a huge gap between playing with the theoretical possibilities and dealing with political realities.



Tax code politics



The home mortgage deduction "is a very popular provision," said Stephen Ellis, vice president of Taxpayers for Common Sense, a group focused on government waste and subsidies to the private sector. Ellis said deductions for child care and college tuition enjoy similar broad support.



"President Obama’s campaign ad ignores the context in which those tax breaks would be ‘taken away’," Ellis said. "They are only going to be significantly reduced or eliminated in the context of fundamental tax reform that reduces the tax rates for the same filers."



Matt Jensen, an economist at the conservative American Enterprise Institute, has written in defense of the feasibility of Romney’s plan. He said the Obama ad gets ahead of the process that would take place on Capitol Hill.



"I do not believe Romney would do things that he has explicitly said he would not do," Jensen said. "More likely, he (or Congress, really) would tinker with other aspects of the tax reform plan."



Romney, Jensen said, would bring certain principles to the tax plan he brings to Congress. The details of how those principles play out cannot be judged today.



We should note that through his running mate, Paul Ryan, Romney has associated himself with a budget plan that would eliminate the American Opportunity tax credit for college tuition. This is not specifically part of the Romney tax plan but it would hit the pocketbooks of some 3 million households, some of whom would be in the middle class. The credit is worth as much as $2,500 for each college student.

Tuition tax deductions, in contrast to the more valuable tax credits, are also in the tax code. Parents can reduce their taxable income by up to $4,000.



Our ruling



The Obama campaign ad says Romney’s tax plan "could take away middle-class deductions for child care, mortgages and college tuition."



Romney has said he would not reduce the mortgage deduction and has promised not to increase taxes on the middle class. However, he has failed to provide enough details for analysts to model what his plan would actually do.



There are reasonable concerns that the numbers in Romney’s plan don’t add up. The ad assumes that to get the numbers right, the worst possible outcomes for the middle class are likely. It says some major deductions could be taken away.

At PolitiFact, we put the burden of proof on the person speaking to back up his or her claim with evidence. The Obama ad is very specific about which deductions might be at risk. The Romney plan might be unrealistic and intentionally vague, but the Obama campaign is filling in the blanks with specific deductions that would appeal to middle-class moms. Romney hasn't said he intends to take away those deductions. And he's specifically said he won't touch the largest of those deductions, the mortgage deduction for the middle class.



We rate the statement Mostly False.