You won't know what your tax difference is unless you complete your 2018 taxes using the 2017 tax code, and even that won't be completely accurate due to CPI changes in brackets, exemptions, etc.
e.g. Once your 2018 taxes are complete under the new temporary Individual tax changes, enter your 2018 data in TurboTax 2017. That will give you the best indication of your temporary tax change.
The withholding tables were adjusted. The middle class began receiving their nominal net increases and have already forgotten. They're in for a rude awakening if they think they'll be receiving a big tax return in early 2019.
In any event, there's a reason no Reps are touting the tax changes in the mid-terms. It was a permanent massive tax cut for corporations and certain other business activities. It was a nice, albeit temporary, tax cut for the top ~10% of earning households, and a nominal, temporary again, tax cut for the middle class. It will be a tax increase for households with decent income (~$100K-$200K), but large state income tax and property tax bills.
It's difficult to cut the middle class' federal income taxes when they pay so little already, relative to higher earning households.
