So, they want to penalize people who live in homes larger than 3,000 square feet.

One of Capitol Hill’s most experienced and powerful legislators is drafting a “carbon tax” bill that would do precisely that. Rep. John Dingell (D-Mich.), chairman of the House Energy and Commerce Committee, expects to introduce comprehensive climate change reform legislation once Congress returns next month.

Besides imposing hefty new federal taxes on gasoline, the forthcoming bill will, in Dingell’s words, seek to “remove the mortgage interest deduction on McMansions - homes over 3,000 square feet.” Dingell said he recognizes that proposals like these will be highly controversial, but he believes they are essential to achieving the environmental goal of reducing carbon emissions by 60 percent to 80 percent by the year 2050.

First off, the idea that this has anything to do with "saving the environment" is bunk.

It's just a sneaky way to raise tax revenue, of course. And it targets a small group of people who we all love to hate: the ridiculously wealthy. (As an alternative, may I suggest we charge another tax on people who drive Hummers?)

Why don't I support it?

I don't think it's fair, basically.

There is already a limit on the amount of loan interest you can deduct on your federal tax return.

Either allow the deduction or get rid of it, don't start messing with the limits.

More: Tax could cut big-home deductions - By Kenneth R. Harney, The Boston Herald