The policy as I understand it (and this not really my area) is to encourage home ownership under the assumption that home ownership = good for USia. Credit card interest deductions were also to "help the economy" through encouraging people to buy things on credit - i.e. spend more. Of course, this led to a disaster of people who bought what they couldn't afford, resulting in higher bankruptcies etc which increased the cost of borrowing to everyone else as the big morons went broke. Now us so-so morons pay more for every credit purchase and the banks give us less interest...trickle down in the real world (expenses trickle down, profits do not).

Ugh, this revival of coded trickle-down talk is why I don't like the McCain tax plan. It's freedom to the upper classes is essentially based on a re-worded trickle-down assumption about the economy, which has been disproven repeatedly.