They just gifted to American businesses (corporate and pass-thrus) a $1.8 trillion tax cut over the next decade---most of it permanent.
And, seemingly, it was as easy as pie to accomplish. That's because beforehand they had written themselves the equivalent of a parental note to the teacher saying it was OK to borrow $1.5 trillion of the cost.
This meant, in turn, they didn't have to squeeze K-Street too hard for offsetting "payfors". And off-setting spending cuts weren't even on the table.
Moreover, the fiscal ease of it was aided immensely by the fact that they wrote the big revenue-loss hogs on the individual income tax side in disappearing ink---otherwise known as a "sunset".
For instance, the GOP pols have been talking up a storm about doubling the standard deduction to $24,000 per family and raising the child credit from $1,000 to $2,000. Absolutely pro working family, that. Woo-woo!