After last night’s Super Tuesday victories, Mitt Romney’s longstanding lead in the GOP primary looks increasingly solid. His policy plans, however, are as flimsy as ever. Indeed, exploring his economic policy proposals is rather like touring a Hollywood backlot. Like a street façade on a movie set, Romney’s economic plans are designed to project an outward appearance of functionality. But when you look behind their cleverly made-up fronts, there’s nothing to see. Romney’s policy offerings on taxes, spending, and entitlements consistently lack crucial structural details; his campaign seems intent on emulating the outward appearance of policy proposals without providing anything that’s actually workable.

Take Romney’s proposed overhaul of the tax code. Vague on details and short on substance, it’s more like a press release than anything resembling an actual plan to rewrite the country’s massive, complex tax code. The few details it does reveal tend to focus on the goodies Romney would like to offer and less on their price. Romney proposes an across the board tax cut along with cuts to the corporate rate and various other reductions, including a repeal of the alternative minimum tax. Combined, the Manhattan Institute’s Josh Barro estimates that Romney’s proposals would reduce federal tax revenues by up to $5 trillion over the next decade.

In keeping with his vow to balance the federal budget, Romney also promises to make these cuts in a way that’s revenue neutral. How? He’s yet to say. The plan indicates that Romney would rely on dynamic tax effects while closing tax loopholes and reducing spending in order to offset the lost revenue. Which loopholes would he snip? Which spending would he cut? Anyone wondering about these questions might as well ask a magic eight ball, which would at least provide an answer.

Indeed, Romney has actually employed the plan’s murkiness as a way of responding to outside groups that have tried to tally its economic effects and found it wanting. “I think it’s interesting for the groups to try and score it because it can’t be scored because those kind of details have to be worked out with Congress and we have a wide array of options,” Romney said on CNBC earlier today.

Romney’s tax plan is not the only part of his policy platform missing crucial details. The candidate has also promised to balance the budget while capping federal spending at roughly 20 percent of the economy by 2016. “Achieving this goal,” his campaign website says, “will require spending cuts of approximately $500 billion.” Romney would have voters believe that he has laid out exactly which cuts he would like to make: “I favor deep cuts in federal spending,” he wrote in a recent op-ed for The Wall Street Journal, “and I've previously outlined exactly where I would cut.” Except that he hasn’t.

Romney’s “cut the spending” campaign web page does identify some savings. But many of the figures his campaign cites are, to put it kindly, aspirational. He takes credit for $100 billion in cuts from “empower[ing] states to innovate.” Block granting Medicaid as part of this would save some money—about $28 billion a year, according to the Congressional Budget Office—but there’s no indication as to where the other $72 billion would come from. He also suggests he’ll cut $60 billion through endlessly convenient reductions in “waste and fraud,” which may as well be a proposal to save money through the acquisition and planting of magic budget beans.  

Even if we take Romney at his word, all of the cuts he lists add up to about $320 billion. Where will the rest come from? It’s telling that his plan focuses on small-bore spending cuts to Amtrak and Planned Parenthood, which would reduce federal expenditures by less than $2 billion annually. Moreover, making Romney’s tax plan revenue neutral would require even more budget slashing beyond the basic budget balancing. If he is not willing to identify additional cuts now, is there any reason to believe he’ll do so later?

Romney’s tentpole entitlement reform is similarly evasive. He’s promised to cap Medicare spending through a modified voucher system known as premium support, but won’t say how large the vouchers will be, or how fast they’ll be allowed to grow. Given that the primary budgetary benefit from premium support is to restrain the growth of Medicare spending, the plan is effectively useless without this figure. This is Medicare reform with its spine removed.

Romney has taken to framing his campaign in part around the goals of “less debt” and “smaller government.” These are central themes to his candidacy, and yet Romney’s actual proposals remain mysterious at best, unworkable at worst. The former governor has not only refused to say how he would cut federal spending, he’s explicitly ruled out two of the biggest expenditure categories: defense spending and Medicare, where he’s declared that he’ll reverse cuts made by President Obama. We don’t know how Romney will cut spending. But we know how he won't.

Peter Suderman is an associate editor at Reason magazine.