Loophole #1: Every taxpayer gets the same deduction for cash donations, ie, they are subtracted from your total income so it's as if you never earned the money. Had you ket (eg) the $1, you would (mayne) have paid some taxes on it. So your loss for donating is something less than $1.
However, property (and stock, etc) donations work a bit differently. Whatever you paid for the stock or property doesn't matter, you get to deduct its current market value.
Why is that a loophole? Ted Turner bought an island in South Carolina for chump change about 30 years ago. 20 years ago he donated it to the state as a preserve. The value of the property was based on "appraisals" which put it over $20 miilion. He got to deduct that from income . . . without ever having paid any tax on the gain. This deduction was worth far more than the <$1 million he paid for this undevelopable island.
Loophole #2: Income on Municipal Bonds is Federal tax free, and state tax exempt if the Municipality is within your tax state. States take advantage of this, knowing that people in the top tax bracket can accept a 40% lower rate of return - or even less, depending on the State - and a Municipal Bond will still be attractive. So the rich can get higher after-tax returns through Munis than through other "safe" investments.
This may be a loophole, but usually its the rich who invest in Munis, and the "people" get to borrow money to finance projects - and in some states, state employee benefits lol - at a much lower interest rate.
The first loophole should probably be closed . . . but it *will* reduce charitable donations significantly. The second loophole should probably not be closed, because it will cost us all a lot more money through higher interest rates.
Tax law is complicated, as even these two simple examples show. And every change has unintended consequences.