By Stephen Kranz, Diann Smith and Mark Nebergall (January 21, 2018, 7:00 AM EST) -- On Dec. 22, 2017, the president signed into law the Tax Cuts and Jobs Act, P.L. 115-97.[1] The TCJA ushered in the first reform of the U.S. tax system in more than 30 years. The approach to tax reform taken by the TCJA is to broaden the business tax base and reduce the tax rate; for corporations, the rate is reduced from 35 percent to 21 percent. Because most state income tax regimes key off of federal taxable income, the base-broadening provisions of the TCJA will have implications for state income taxes, but without the tempering of the federal rate reduction. This article highlights the possible impact on state income tax liabilities stemming from the base-broadening provisions in the TCJA....