HispanicBusiness

Robert D. Reischauer, a former director of the Congressional Budget Office, expressed the consensus of many independent analysts: "The proposals by Romney are politically unachievable, and the president's proposals, while achievable, are too modest."

The plans of both, analysts say, would leave the public debt continuing to rise over the next decade as a percentage of gross domestic product, the measure that economists favor. Though Mr. Romney's plans are more difficult to judge, given his lack of specifics, by some analyses he would do less to reduce annual deficits in that time than the president would, considering his position against raising taxes, his call to increase military spending and the fact that his proposals to remake Medicare -- the largest contributor to long-term deficits -- would not kick in until after 2022.

One analysis, from the Committee for a Responsible Federal Budget, estimated that the debt would grow to at least 86 percent of gross domestic product under Mr. Romney's plan over the next decade, from 73 percent now. Under Mr. Obama's policies, the debt would increase slightly after a decade, to about 77 percent of G.D.P., according to the Congressional Budget Office. Many analysts say that a nation's debt should not exceed 60 percent to 70 percent of G.D.P.

Mr. Romney wants to cut taxes by $5 trillion on top of the Bush- era rates and keep military spending at a level requiring $2.3 trillion more than projected in the decade. But he also pledges to offset those costs to avoid adding to deficits, paying for the tax cuts by closing tax breaks and for the military spending by cutting domestic programs. In effect, he has challenged himself to find $7 trillion in savings before he even turns to deficit reduction.

Erskine B. Bowles, a Democrat who helped lead a bipartisan debt commission for Mr. Obama in 2010, said: "That means you've got to make really big cuts in those areas that we have got to invest in to be competitive in a knowledge-based global economy: education, infrastructure, research. Also, you've got to make really big cuts in the income-support programs that take care of the disadvantaged."

Independent analyses have also outlined the difficulty Mr. Romney would face in finding enough savings in the tax code to pay for his tax cuts. For all the talk of loopholes and tax dodges, the real money is in the popular deductions and credits -- for employee health benefits, mortgage interest, charitable donations, state and local taxes, child care and college tuition -- that benefit many middle-income Americans.

But Mr. Romney has said he would not raise taxes on the middle class. His chief economic adviser, R. Glenn Hubbard, the dean of the Graduate School of Business at Columbia University in New York, said Mr. Romney would shrink his tax cuts before he would break that promise. The Romney plan also counts on economic growth to generate some new revenue to pay for tax cuts.

Because Mr. Romney would delay his Medicare changes for a decade to exempt current beneficiaries and those nearing eligibility, the savings would not help him keep his promise to balance the budget in 8 to 10 years. That goal is two decades sooner than Mr. Ryan would reach balance in his House budget, indicating how much deeper Mr. Romney would cut domestic programs than Mr. Ryan would.

Mr. Romney has characterized his call for the repeal of Mr. Obama's health care law as a budget-saving measure, but the Congressional Budget Office has said that repeal would add $800 billion to the deficit over the next decade.

Mr. Romney's main proposal for reducing deficits in the short run is to cap all spending by the end of his term at a level equal to 20 percent of gross domestic product, the average for the 30 years before the recession, before spending on stimulus measures, unemployment aid and retiree benefits helped drive spending to the current 23 percent.

But long before the recession, forecasts had U.S. spending rising above 20 percent of gross domestic product in this period, largely a result of the pressures of an aging population. So the Obama camp argues that a 20 percent cap is unworkable.

More likely to get squeezed, whoever is elected, and certainly under Mr. Romney, is the wide range of domestic discretionary programs, covering education, science, law enforcement, veterans' care and more. These programs, which Congress finances annually, get a relatively small and declining share of the U.S. budget as spending grows for entitlement programs, the military and interest on the debt. Last year's bipartisan deficit deal called for cuts of more than $1 trillion over 10 years. Many analysts doubt that Congress can agree to those reductions, yet Mr. Romney's cuts would come on top of them.

Mr. Obama's plan, which would seek to balance spending cuts and tax increases, has been attacked from opposite sides -- from conservatives for raising taxes and from budget watchers who agree with Mr. Hubbard that the president cannot finance the government he wants simply by increasing taxes on the rich.

"We're going to have to raise taxes more than the president has proposed, and on a broader swath of taxpayers," Mr. Reischauer said.

Mr. Obama's budget "comes out in a better place than we are now," said Robert L. Bixby, the executive director of the Concord Coalition, a budget watchdog group. "But it's not like it's full of bold proposals. And it doesn't add up to a sustainable outlook."