这篇文章说是2018， 所以加州的兄弟今年还可以多交州税

https://www.vox.com/policy-and-politics/2017/11/29/16709526/tax-reform-republican-plan-take-effect

Republicans are on track to pass a tax bill by the end of the year, and if they’re able to stick to that schedule and the bill is signed by President Donald Trump, it would go into effect on January 1, 2018. The sweeping overhaul of taxes would reduce rates for corporations and individuals (although individual tax cuts would eventually expire), and would also repeal the Affordable Care Act’s individual mandate, effectively kicking 13 million people off their insurance, according to the Congressional Budget Office.

But Americans won’t see a big difference in their tax return when they sit down to file this spring; the proposed cuts in the bill contains would show up the following year.