The conept he is refering to is not unlike what we did in the early 80's where marginal rates were dropped and things like credit card interest among other things were no longer deductible. This created enormous capital formation and was some of the best work ever done in that area.
Essentially the details can't be explained because they'd have to be approved congressionally. So what ever deductions that are kept or eliminated will be part of a negotiation. However, they'll be something like for example a max cap on deductions of an arbitrary # of 20-30k. The percentage of total taxes collected by the wealthiest will not change very much since they in effect already pay nearly all the income tax collected by the treasury as it is. The goal is more simplicification of the tax system to move towards more efficiency. The reality is that no matter what the gov't does with the tax law they always collect 17-18% of GDP. That number over time is relatively constant.
Our problem in this country is not reveue collected. The Gov't takes in more than it needs. It simply spends too much. Regardless of how much comes in, congress always has and always will find a way to spend even more. However, an enormous amount of resources are wasted individually as well as at the corporate level attempting to manuver through a field of land mines in an overly complex tax system.