It sounds like a simple enough idea.
To pay for proposed big tax cuts for companies and households, all you have to do is get rid of many of the deductions, exemptions, loopholes and other tax breaks that cost the Treasury billions in uncollected revenues.
But like anything involving the U.S. tax code, the task of eliminating those loopholes is far from simple. The reason is that each of those "loopholes" is also a tax windfall, usually fiercely defended by lobbyists and members of Congress representing millions of their constituent businesses and households.
While corporate "loopholes" may draw the biggest ire from voters, individual taxpayers are by far the biggest beneficiaries of federal tax breaks. Some taxpayers may not even be aware of the breaks they're getting.
The costliest loophole, for example, is the tax treatment of health insurance benefits paid by employers, which can represent a sizable portion of a given worker's overall compensation. But because that benefit is not taxed as income, the Treasury loses out on billions of dollars every year.
For the fiscal year that ended last week, that provision alone cost the government some $221 billion, more than the deduction for state and local taxes, ($91 billion), the mortgage interest deduction ($69 billion) and charitable deductions ($48 billion.)