With all due respect; this is a very stupid analysis.  You say "Under current law, taxpayers who itemize (only 30 percent do) are permitted to deduct from their federal taxable income many of the taxes they pay to state and local governments. The deduction, which will cost the treasury an estimated $1.8 trillion over the next decade, chiefly benefits wealthier taxpayers in high-tax states such as New York, California, and New Jersey. About 88 percent of the tax break's value accrued to those with incomes in excess of $100,000 in 2014, and only 1 percent flowed to taxpayers with incomes below $50,000."  

The top 25% of income earners ($77,700 and up) pay 87% of Federal income taxes. So if the under $50,000 brackets pay little to nothing why would anyone think that "only 1%" of such a  deduction would flow to them?  By the bye, it "COSTS" the Treasury precisely nothing to reduce taxes.  The Treasury produces nothing, earns nothing, and pays nothing. All costs are taxpayers'.