The Red State blog also notices that Obama’s reduction of the charitable tax deduction will negatively affect charities in this country and concurs with my supposition of the motive:
With this proposal, President Obama is saying as directly as it can be said that the federal government is better able than private citizens and the charities they support to decide how these donation dollars are best distributed. Conservatives, by contrast, believe in the principle of subsidiarity — which in this instance means that charity is best performed at the most local and immediate level possible, and by “mediating” institutions rather than large, distant, and bureaucratic ones. This is not an abstract doctrine; it is based on the accumulated wisdom of the ages.
My take on this from a couple of days ago.