Any citizen including Billionaires who wish to make a general donation to the United States government may send contributions to a specific account called "Gifts to the United States." Why wait for tax rates to be changed.
Gifts to the United States
U.S. Department of the Treasury
Credit Accounting Branch
3700 East-West Highway, Room 622D
Hyattsville, MD 20782
PS. You can have one of your tax lawyer’s double check that address.