Dive summary:

• One argument against touching the mortgage interest deduction in reforming the U.S. tax system is that it is one of the foundation blocks of the American Everyman's dream of home ownership.
• Research into how the tax benefit works out takes some of the steam out of that claim, showing that 75% of the dollars saved from taxation go to the top 20% of taxpayers as measured by their annual incomes – those making $200,000 or more annually.
• Another bit of information that deduction supporters should be ready to meet is that the deduction is most heavily used in a relatively few large metropolitan areas rather than across the nation's smaller communities.

From the article:

The home mortgage interest deduction is America’s largest housing program. ...