For as long as Americans have paid federal income taxes, they’ve been able to subtract some of what they pay to their state and local governments from their taxable income. This federal deduction for state and local taxes — the SALT deduction,

U.S. Rep. Elise Stefanik said she was the “deciding vote” on a megabill that quadrupled the maximum state and local tax deduction.

The fight has pitted the GOP's top tax writer against a determined bloc of House Republicans from high-tax states. It has also created divisions between the pro-SALT Republicans.