If you add it all up though, someone who was itemizing before is not going to explicitly lose out here. But they're not gaining anything from the bill, while many others are. Of course that means they're implicitly losing out instead.
well, most ppl who are currently deducting their mortgage will be majorly cut back. Or SALT. Or charity.
For example, if you currently have 10k of local income tax, 10k of property tax, 8k of mortgage interest, and 10k of charity. So today you are deducting 38k, which is 26 more than the standard deduction.
Even assuming all of those remain deductible, since the standard deduction is now 24 (and that doesn't give you much, since they traded that for your and your wife's personal exemption), you deduct 38k which is 14k more than standard deduction. So you lost 12k of deduction.
But really, if you also now can't deduct the state income tax, you only have 28k, so you lost 22k of deduction.