Alan Viard has written a sensible and informative post:

The ongoing debate about the potential role of tax changes in a deficit reduction package appears to be descending into a clash between rival misperceptions. One fallacy rejects all tax increases, including measures, such as repeal of the ethanol tax credit, that level the playing field and thereby allow economic resources to be allocated by the market rather than a distortionary tax system. Some who oppose this fallacy embrace an alternative fallacy holding that any measure that broadens the tax base rather than explicitly increasing marginal tax rates must be conducive to economic growth and efficiency. In reality, as I have observed elsewhere, some base broadening provisions actually tilt the playing field and impede efficiency. In the end, of course, each proposed tax change must be weighed on its own merits.

Viard goes on to recommend an intriguing tax proposal from his colleague Thomas Miller:

[T]he income-based itemized deduction cap is half-baked. Although there is some merit on fairness and efficiency grounds to limit tax subsidies for consumption of goods and services like health insurance and housing—particularly for upper-income earners—the White House proposal does nothing to help lower-income Americans in return. A better balance would involve setting a single rate for such deductions, raising the deduction rate for lower-income taxpayers and lowering it for higher-income ones, until they meet at a revenue-neutral level—equivalent to a fixed-percentage tax credit for such favored expenditures that provides the same proportional “pre-tax discount” for all purchasers.
This would appeal to Democrats’ perpetual lust for income redistribution through the tax code, signal some sensitivity to fairness concerns by Republicans, and create another precedent for moving more comprehensively toward a flatter, if not flat, rate version of income tax reform. Providing greater deductions to those who incur greater expenses to produce more income is eminently defensible; handing out extra portions of tax subsidy dollars to higher-income taxpayers to consume more, and higher-priced, consumption goods and services falls short on both efficiency and equity grounds.

Miller goes on to suggest that this flat-rate approach to deductions apply first to health insurance and home mortgages. Though it certainly sounds cumbersome, the idea has merit.

P.S. Right now, tax deductions become more valuable as you pay income tax at higher rates, e.g., if the bulk of your income is above $372,951, a tax break is much more valuable to you are subject to a lower tax rate. A fixed-percentage credit would set the value at, say, 30%, which would be a boon to those who pay less than 30% while taking away some of the benefit from those who are subject to a higher tax rate.