It would, of course, be possible to reduce the deficit by eliminating medical care and pensions for the elderly and disabled, while continuing to let multi-millionaires exploit loopholes in the tax code to pay less taxes than many people working at minimum wage, but this is not only a bad solution but a cruel and inhumane one.
A major way to reduce the deficit is to look at tax breaks for corporations and the very rich as subsidies to the rich and concentrate on eliminating them. Also, by allowing US companies to offshore financial activities and reduce the taxes they pay, we are essentially subsidizing the export of American jobs; we should cease doing so.
Another major area in which we can reduce spending is defense. We currently spend more on defense than any other nation in the world, and by reducing our involvement in foreign wars, could reduce our expenditures dramatically.
Finally, we could reduce our current account deficit dramatically by massive investment in renewable energy.