Interesting article in the Washington Post:  Deductions Are A Tempting Target, by Kenneth R. Harney:

Federal tax benefits for homeownership are among the heftiest and most popular of any in the Internal Revenue Code: An estimated $81 billion for mortgage interest write-offs, $15 billion for local real estate taxes and $24 billion for capital gains exclusions this year alone, according to the congressional Joint Committee on Taxation. But who really gets those tax-code goodies? Who gets to write off the most? New research offers insights into where the billions of dollars in annual mortgage interest and real estate tax deductions flow, state by state, congressional district by congressional district. The research was conducted by the National Association of Home Builders, using the latest Internal Revenue Service data available, from 2003. Among the findings:

Homeowners in a single congressional district in California — the 14th in Silicon Valley — took more in mortgage interest write-offs than all the residents of six states combined. Homeowners in that district claimed $3.2 billion in mortgage interest deductions during the year covered by the study, compared with $2.9 billion by all the residents of Vermont, Wyoming, West Virginia, Alabama and North and South Dakota. The average deduction in the 14th District was $35,000, compared with an average of $9,500 for homeowners nationwide.

For more details, see the NAHB press release, New Study Details Importance of Homeownership Tax Preferences in All Congressional Districts.