The source is either a joke or heavily partisan.
The (true) Republican plan, which was part of the Simpson-Bowles commission report, involves two constraints:
1. Neutral with respect to revenue
2. Neutral with respect to the relative share of taxes paid by taxpayers at income levels of income
So, let’s say the the child credit goes, then rates come down to compensate. Ditto mortgage interest deduction. Ditto everything else. Except maybe there are some phase-outs. Initially, the major effects on the budget involves decreased administrative costs and increased compliance. In the long-run, there would be additional budget impacts from increased work and investment.
we need tax cuts and simplification, not revenue neutral malarkey