This is what happens if the Democrats (and pro-SALT Republicans) have their way and the tax cut is not extended (based on a handy summary from the Brookings Institution):

• • • Millions More Americans Will Have to Itemize Deductions: If TCJA expires, the standard deduction for a married couple will be cut to $16,525 in 2026, versus $30,725 if the tax cut remains.  This means about four times as many Americans will have to itemize deductions making tax preparation much more complicated.

    • Individual income tax rates rise: TCJA lowered marginal income tax rates for all tax filers. The highest tax rate will rise from 37% to 39.6%.

    • State and local tax (SALT) deduction: TCJA imposed a $10,000 cap on the deductibility of state and local taxes (SALT).  If this provision of the TCJA expires, all state and local taxes will be deductible, primarily benefiting rich people in high-tax states.

    • Child Tax Credit Cut In Half:  If TCJA is repealed the tax credit for each child under 17 falls from $2,000 to $1,000, penalizing families with kids.

    • Small business income tax rises by 25%: TCJA provided a 20% deduction for most small businesses.  If the bill is not extended the tax on qualified small businesses rises by that amount.

    • Alternative minimum tax (AMT) Hits Millions More Families: Failure to extend the TCJA would mean roughly seven million more families hit with the unfair AMT.

    • Twice as Many Families Hit with Death Taxes: The TCJA doubled the estate tax exemption. If this provision expires the exemption in 2026 will be cut from $28.6 million to $14.3 million for married couples.